Hi Kelgarv! I do Iyengar yoga which is a form of hatha yoga, the physical type of yoga. I focus on relaxation, strength and muscular balance. The best way is to find a class with a teacher who has been practicing for at least 10 years, absolute minimum of 5 years. There are a lot of teachers who have practiced yoga for just a few years. I personally think that's not long enough.
There are also lots of good video tapes...one good series is the yoga journal or Gaiam series - look for Rodney Yee or Patricia Walden as the instructor. They have titles like yoga for beginners, yoga for strength, yoga for relaxation...check out your local library!
I know of lots of good books. I actually taught myself from a book. Let me know if you'd like titles. Good luck - I'd love to know how you do!