What is the process of conversion to Orthodoxy from Anglicanism/Catholicism

It's not that complicated, though probably falling more into what you call "classes and such."

Some time ago I read a pretty good book called Becoming Orthodox by Peter Gillquist. That might be helpful, as I believe his story involved a journey of already baptised, practicing Christians.

And here's a good article from the Orthodox Church in America: Steps to “becoming” an Orthodox Christian

An excerpt:

Assuming that, after subsequent visits, you grow into the conviction that Orthodox Christianity is the fullness of Truth as revealed by Jesus Christ and discern your desire to embrace faith in Our Lord in its fullness, make your desire known to the parish priest, who will initiate the period of instruction and spiritual formation that eventually would lead to your reception into the Church.

This could take some time—perhaps a year or more, depending on a variety of circumstances—and should not be “rushed.” Just as we pray that God’s will, not our own, be done, so too we pray that we might embrace the faith in God’s time, not our own. Conversion involves a change or transformation in vision, direction and heart, one rooted in repentance and the acknowledgement of Our Lord as the One Who is “truly the Christ, the Son of the Living God, Who came into the world to save sinners.” (emphasis added)

I am a convert, so I can tell you the process I went through (basically "classes and such, then Chrismation" as you put it).

It starts with a lot of learning and coaching from the Priest and from other experienced Church members. I actually went to classes. If you decide to become Orthodox, the Priest must be sure you are choosing to convert for the right reasons. If so, you select a sponsor (aka God-mother or God-father) who is basically the church member who acts as your spiritual parent. And then you become a Catechumen in a small ceremony that involves stating a renunciation of the beliefs of the church you came from (so this is different depending on if you were Catholic or Evangelical or something else). As a Catechumen, you still cannot take the Eucharist (Communion) but are otherwise considered part of the church. After a time of being a Catechumen and continuing to learn and get familiar with the Orthopraxia (Orthodox practices such as crossing yourself, kissing icons, etc.), then it is decided between you and the Priest when to be Chrismated. If you have not already been baptized in the name of the Trinity then you would be baptized as well - in your story if they already have, then Chrismation would be the only thing needed. For me, the process of starting to take the classes through to Chrismation took about a year and a half.

Different jurisdictions do it differently I think. Basically you will end up doing what the bishop says, most of which will chrismate you in the West if you were baptized in the name of the Trinity and believed in the incarnation. But there is a bit of debate on the issue and I remember a bishop being surprised when I told him I was baptized in the name of the Trinity, but not by triple immersion, and therefore the external form of the baptism was not maintained.

I have talked to 3 different jurisdictions about the issue and all 3 would receive me by chrismation, but I do know of a couple of places that would baptize me here in America if I wanted to follow the guidance of my own wisdom.

It is important to note that advice on what converts to baptize or simply chrismate has been an issue in a lot of the councils throughout the centuries. So there is no plain answer. For instance, my priest encouraged me to write a letter to our bishop about how I was raised and baptized because I wanted clarity and guidance about my personal position.

One complicating issue is that iconography and veneration of the Theotokos as the Mother of God are things not things practiced in a lot of Protestant congregations, which are often affirmed as testaments to orthodox Christology in Eastern Orthodoxy.

Within the Roman Catholic Church, the normal order of progression is Baptism as an infant, first communion during elementary school, and confirmation during high school.

Within the Eastern Orthodox Church, a baby received into the Church receives all three of these Sacraments at the same time: he/or she is baptized and chrismated (analogous to RC confirmation), and then receives Communion at the first Liturgy following his or her baptism/chrismation. Usually, baptisms occur before a Liturgy, so a newly received infant receives his or her first Communion on the day of his or her baptism.

The Eastern Orthodox Church does not recognize any sacraments of any other church with the exception of Baptism. Usually, a Roman Catholic (and I believe Anglican) being received into the Church is not (re-)baptized, but this is not universal. For the purpose of your novel, however, you can probably assume this is the case.

So, again for your novel, on the day of a Roman Catholic or Anglican convert's reception into the Eastern Orthodox Church, you can expect them to be chrismated and then to receive Communion at the Liturgy following their chrismation. Usually, newly "illumined" converts are brought to the front of the communion line by their godparents and they usually hold a candle as they approach the chalice.

I am writing all of this from personal experience: I am an RC convert to Eastern Orthodoxy.

I am sure you can find videos of the actual rite on YouTube. Just make sure that you are seeing the reception of a layperson and not clergy. There is a different process for receiving RC or Anglican clergy into the Eastern Orthodox Church (where they usually begin serving as priests after they are received).

As far as adult preparation, one should expect a minimum of 6 months, maximum of 1 year of preparation, some formal, some informal. But it may stretch out for much longer, depending on the convert. I know one Baptist who took 14 years. Each week he came to the priest with a new set of questions and objections. When all of these were exhausted, he decided to be received. (He came to the church to argue with the priest over the word "Orthodox" being displayed on the church sign, as he saw the Eastern Orthodox Church as being completely at odds with "orthodox" Christianity).

When I converted to Orthodoxy (from Roman Catholicism) at the age of 27, the following process took place:

1. As part of a special service created for this kind of thing, I had to renounce the teachings of the Roman Catholic Church (thrice if I remember correctly).
2. Then I had to state the acceptance of the teachings of the Eastern Orthodox Church.
3. Side note: There was no need for a godfather or an immersion into water as the Roman Catholic baptism is recognized as being Trinitarian (I was baptized in the name of the Father and the Son and the Holy Spirit).
4. And lastly, I was annointed with the Holy Myrrh on my hands, feet, back, chest and forehead, the same as babies are after the baptism itself. This annointment is not performed in Roman Catholic baptisms.

With Anglicans being Trinitarian as well, I would expect the same procedure to take place.

If you want minute details of the conversion service, I think it's public on the Web. In Romanian it is for sure, and most probably in other Orthodox majority languages. Not sure though if you can easily find it in English. Good luck!