Writing music in a historical style, such as Baroque music, is largely a matter of theory, so I think you should be well-equipped enough to start. Most of the time (in my experience, all the time), a composition teacher will not want you to write Baroque music, since it is very far from cutting-edge.
I must confess that I don't know of any resources that teach one form at a time, and in fact, I don't know of anything that teaches any Baroque music aside from fugues. I agree with the above comment that says not to start with fugues -- there are easier things to start with. I also wouldn't get to fugues last, since they tend to be incorporated into longer works.
You mentioned chorales. I assume you have been harmonizing chorales for your theory studies, so that seems like a good place to start. Instead of harmonizing someone else's melody, you would write your own melody and harmonize that.
Another good place to start would be the dance forms (allemande, etc), since the general style and accompaniment are already set in place for you. Shorter forms, like French overtures, are also easier to write. I find it easier to compose if I am locked in to a set of parameters. The blank page can be a little intimidating.
Your main resource is going to be other works by Baroque composers, who you probably know better than I do. If you get stuck, take a break and look at Bach or Vivaldi or whomever you prefer. See what they did or didn't do, and try to draw inspiration from that. Once you listen to enough of those composers, you start to develop an ear for their style, and in fact, one of my theory teachers told me something like, "To learn to write a fugue, you could go to a book about fugues, but you would be better off just listening to fugues until they make sense."
Mostly -- and I apologize for this fairly generic advice -- you just need to start composing now, and worry later about what order you should do things. People definitely compose with less theory knowledge than you have. Composition is a skill distinct from theory, and you might not be satisfied with your results at first, but just keep trying. Ideally, you would want to compose a little every single day, but I can't say I always do.
This reply has run a little long, so let me recap a little:
1) I don't know of any resources that go form-by-form, but the best thing to do is to listen to Bach et. al., and compose as often as possible.
2) Analyzing scores is probably more useful than any book.
3) If I were in your position, I would do something like: Chorales and other short-form works, then dances, then imitative counterpoint and longer works.