Great advice above. For my money, you can't beat a Martin Hunter. Older Bears and Brownings, as well as Shakespeare and Pearsons would be a good place to start. Don't go too heavy, 45# or so to start. I assume you are coming over from the dark side, so remember that you are holding the full weight of the bow, not 20% of it.
By overbowing yourself, you can develop bad habits that will stay with you for a long time. Don't ask me how I know this!
You might also want to check out the Quinn bows, and Samick from Lancaster Archery. Both have interchangeable limbs, and you can buy new ones as your ability increases.
Good luck!