What are the Core Teachings of Buddhism?

But there is a Buddhist bible. It is the Tipitika (Three Baskets). It was recited by monks three months after the Buddha's parinibbana. The Suttas were recited by the Ven. Ananda, the Buddha's attendant monk. The Vinaya was recited by the Ven. Upali. There is some scholarly dispute as to whether the third part of the Tipitika, the Abhidhamma, was recited at the same time, or if it is a later addition.

The ATI website has a Path to Freedom series which provides a "A Self-guided Tour of the Buddha's Teachings" based on the Pali Canon.

Of these, there is an overview of The Dhamma, which are the teachings of the Buddha. Inside each sub-page, there are quotes from the Pali Canon.

If you want to buy a book, I recommend "In the Buddha's Words" by Bhikkhu Bodhi. This is an anthology of the Buddha's teachings from the Pali Canon.

The core teaching is summarized by the words:

• Not to do evil, (Unwholesome deed/action will lead to bad karma/suffering)
• To cultivate merit, (Wholesome deeds will lead to a better self)
• To purify one's mind, (It will help us to view the world as what it really is)
• This is the teaching of the Buddhas.

Above is from Dhammapada verse 183, the one in brackets are my understandings. Below is the original words in Pali followed by Mandarin/Chinese.

• sabbapapassa akaranam 諸惡莫作
• kusalassa upasampada 眾善奉行
• sacittapariyodapanam 自淨其意
• etam buddhana sasanam 是諸佛教

Some great answers here. I think that the core of Buddhism is expressed wonderfully by the doctrine of the three poisons and their corresponding antidotes. As has been mentioned though, you're going to want to read the 4NT sutra. The foundation of buddhist thought series volume 1 covers what you want in a very accessible way.

Here is the Tipitaka or Pali Canon in English:

http://www.accesstoinsight.org/tipitaka/

From Wikipedia:

The Pāli Canon (Pali: Tipitaka) is the standard collection of scriptures in the Theravadan Buddhist tradition, as preserved in the Pāli language.[1] It is the first known and most complete extant early Buddhist canon.[2][3]

There are also scripture collections for the Chinese and Tibetan traditions which is why folks were asking which tradition you were interested in. But as noted above, the Pali Canon is considered the earlier canon.

To do good deeds, avoid bad deeds and purify the mind. And the practice to attain that is through Sila (morality), Samadhi (Meditation) and Panna (Wisdom).

An idea of the core teachings of Buddha can be derived from the Maha Parinibbana Sutta...the teachings before his final nibbana.

In the sutta, the Blessed One says,

"Now, O bhikkhus, I say to you that these teachings of which I have direct knowledge and which I have made known to you — these you should thoroughly learn, cultivate, develop, and frequently practice, that the life of purity may be established and may long endure, for the welfare and happiness of the multitude, out of compassion for the world, for the benefit, well being, and happiness of gods and men.

"And what, bhikkhus, are these teachings? They are the four foundations of mindfulness, the four right efforts, the four constituents of psychic power, the five faculties, the five powers, the seven factors of enlightenment, and the Noble Eightfold Path. These, bhikkhus, are the teachings of which I have direct knowledge, which I have made known to you, and which you should thoroughly learn, cultivate, develop, and frequently practice, that the life of purity may be established and may long endure, for the welfare and happiness of the multitude, out of compassion for the world, for the benefit, well being, and happiness of gods and men."

Thus, one sees that Buddha directly exhorts the Sangha to thoroughly learn, cultivate, develop and frequently practice the following teachings for the benefit of oneself and many:

1. The Four Foundations of Mindfulness
2. The Four Right Exertions
3. The Four Bases of Power
4. The Five Faculties
5. The Five Powers
6. The Seven Factors of Enlightenment
7. The Noble Eightfold Path

These 37 factors are together called as the BodhiPakkhiyaDhamma or 37 factors of Enlightenment.

Now coming to this comment,

You can find the core teachings of Jesus by reading the Bible, There is no Buddhist Bible. Im so far unable to find a english Pali Canon to read.

To me when people say I must have a tradition to know what the teacher says its like saying you can't explain jesus's teachings cause its to hard with out traditions. You dont have to be catholic, Methodist, Lutheran, Evangelicalism, or even Baptist to simply look up the text an see for your self what he taught, without the dogmas and doctrines to keep you ensnared into a rigid form of the faith an blind to what it means. This examples shows how some traditions an customs keep you from the truth an keep you distracted away from the teachings.

I think, in general when people urge somebody to adopt a tradition, it is because there is a great deal of emphasis on meditation in Buddhism. Without meditation one might know things intellectually but not experientially. For meditation, one might attend a retreat nearby. Dhamma.org - link for 10 day course registration at one of many centres in the world is a great option.

As regards the right teacher and right tradition for oneself, the Kalama Sutta provides great guidance. Herein the Enlightened One says,

'Don't go by reports, by legends, by traditions, by scripture, by logical conjecture, by inference, by analogies, by agreement through pondering views, by probability, or by the thought, "This contemplative is our teacher." When you know for yourselves that, "These qualities are unskillful; these qualities are blameworthy; these qualities are criticized by the wise; these qualities, when adopted & carried out, lead to harm & to suffering" — then you should abandon them.'

"Now, Kalamas, don't go by reports, by legends, by traditions, by scripture, by logical conjecture, by inference, by analogies, by agreement through pondering views, by probability, or by the thought, 'This contemplative is our teacher.' When you know for yourselves that, 'These qualities are skillful; these qualities are blameless; these qualities are praised by the wise; these qualities, when adopted & carried out, lead to welfare & to happiness' — then you should enter & remain in them.

As Buddha himself said many times, his teaching culminates in Liberation By Wisdom. What does this mean?

Our conceptual mind can hardly go beyond the boxes of the concepts it learns. Whatever concepts the mind has, that's how it sees the world, that's the reality for the mind. Usually, our concepts are very coarse, primitive, approximate, simplistic, and sometimes outright mistaken. If the mind thinks there is birth and death, then there is birth and death for the mind. This is what's known as Ignorance.

By training our mind to go beyond such coarse, simplistic, and mistaken concepts (preconceptions), we can liberate our mind from their boundaries, as well as from the suffering they generate, including the suffering of looming death. This means acquiring a more sophisticated view of the world (=wisdom or prajna), including the view of how the concepts are formed, and to what extent can they ever be right (=transcendental wisdom or prajna-paramita).

The main technique for abandoning the coarse preconceptions is relinquishment of attachments, accompanied by analysis. We relinquish emotional and conceptual attachments to preconceptions, biases, and assumptions. We analyze elements of the situation in question until we get a nuanced view going beyond our primitive dualities. Then we no longer get stuck, we become very flexible, very dynamic, very robust. Then we no longer get in trouble ourselves, and can act skilfully for the benefit of all.

I want to know what Siddhartha taught.

Well yes, don't we all want to know that. :-) Though it may seem a bitter pill to swallow. :-/

Some Wikipedia articles FYI:

• Early Buddhism includes a timeline showing the "where and when" of the various schools

• Pre-sectarian Buddhism is an article about "the Buddhism of the Buddha himself". You might not find it interesting/satisfying, but that's life! :-) It says,

  The information on Buddhism in the period before the rise of the early Buddhist schools is based on accounts of Buddha's life and teachings in the scriptures of the Theravadin Pali Canon, and the surviving portions of the scriptures of Sarvastivada, Mulasarvastivada, Mahisasaka, Dharmaguptaka and other schools, most of which are only available in a Chinese translation. Some individual scriptures found in Nepal, however, are composed in Sanskrit. Recently the Gandhāran Buddhist Texts were recovered from Afghanistan. The central body of sutras in these texts is so similar that they are considered to be different recensions of the same text.[15] The accounts in these individual scriptures might be tainted by the particular philosophies of those schools or by translation issues. However, since various recensions of these texts (from various schools) are available, comparisons can be made, and conclusions drawn, to filter out the most obvious of these taints.[16]

  So perhaps you can see why people are interested in the "Pāli Canon":

  The Pāli Canon (Pali: Tipitaka) is the standard collection of scriptures in the Theravadan Buddhist tradition, as preserved in the Pāli language.[1] It is the first known and most complete extant early Buddhist canon.[2][3]

  It was composed in North India, and preserved orally until it was committed to writing during the Fourth Buddhist Council in Sri Lanka in 29 BCE, approximately four hundred and fifty four years after the death of Gautama Buddha.[a]

  Re. the comment saying that "comparisons can be made, and conclusions drawn" about "different recensions of the same text ... (from various schools)", one example of people trying to do that is this document (which I tried to summarize in this answer): to do that they read and compare several 2000-year-old documents written in antique languages and scripts, and that document's bibliography references 50 other papers. And all that is just to analyze one sutta, and even then it's not "canonical".

  So, inferring what pre-sectarian Buddhism was, using the current (sectarian) literature is a complicated job, for scholars of Buddhism.

  It (i.e. the Buddha's dhamma) is a question which also interests practitioners of Buddhism: who are perhaps meant to discover an answer for themselves, by practice, and via teachers.

• Early Buddhist schools seems to be a more detailed history of "early Buddhism", from the time Siddhartha died until their Legacy which includes "the Theravāda school" and "various Mahāyāna traditions".

All the above is to say that it's difficult to be sure of exactly what the historical Buddha taught: especially if you try to disregard Theravada/Mahayana/Vajrayana because they didn't exist in his time.

I hope the above helps to begin to explain some history about why/how/when/where there are different schools.

Your question about the "core teachings" is partially answered by the answers to this other question, What teachings do all schools of Buddhism share? Apparently (or allegedly) those are teachings which all the schools agree on.