Upvote:3
Before I type some recommendations, I would make a suggestion.
One of the ways in which Mahayana Buddhism, as presented by Tibetan Buddhism is classified is in 3 parts- suttrayana, vajrayana and tantrayana. The order is important. Think of the former ones as sort of a pre-requisite. Therefore, without knowing sutras well, the philosophising or reasoning of vajrayana would not be effective and without this, the esoteric practices of tantrayana wouldn't be helpful. In fact, they can particularly be harmful.
For translations: ([Original Author], [book title abbreviated], [translator/editor])
I would highly recommend reading commentaries of the books also (from correct scholars of course).
Other than original texts translated into English and commentaries, I would also suggest the following list of books:
AND of course, please be very careful about the person from whom you pick up Dhamma/Dharma teachings.