Where are you located?
The nov/dec issue of Yoga Journal had a whole bunch of info on studios and teacher trainings, and the mag is a great resource on yoga anyways (or try the web site www.yogajournal.com
) Unless you are already set on a certain style of yoga - do your homework well, there are plenty of trainings around, but i feel that it's essential to get a sound knowledge on anatomy & physiology as well as the asana-practice - to stand above the crowd, so to speak.
Good luck on your search on the path of yoga - and here's my personal reminder - i feel a teacher is never really ready. It's your own practice and example that counts - make it a good one