RE: Another Yoga Question
I hope you get some other answers to this question, but my personal bias is that it is better to have some rea life instruction along with videos.
Videos and books can have terrific instruction, but it is very very difficult to really know what your body is doing, even if you are using a mirror.
It is immensely helpful to have a teacher that can check your alignment and help you correct your form, even given the fact that there are many different ways to do the same pose. A teacher should still be able to guide you to the position that will work for you - what they like to call the "edge".
So that applies to looking for a teacher - find one that is willing to walk through the class helping you in your pose, and avoid classes that have more students than the teacher seems to be able to help. He/she should always encourage everyone to work within their own range of abilities (modify, modify, modify) and be aware of their students weaknesses (stiff shoulders, necks, whatever).
Keep in mind that yoga does originate from spiritual roots so don't be surprised if chanting or meditation is included in the class. Teachers will vary a lot in how much of this they are willing to incorporate into class.
The things that really make it "yoga" instead of "stretching", aside from the spiritual origin, is mindfulness of movement and breath. Both are essential to get the full benefit, IMO.
But even if you don't incorporate these aspects, or find it's just too darn much to think about when starting, you'll still get a lot of flexibility and other physical benefits from just learning the positions, whether from a teacher or a video.
Good luck in your search! If you can, leaf through some copies of Yoga Journal at your bookstore or library and that might give you a better feel for what's out there. As I said, depending on your inclination you can find a teacher that's great at just getting down to business and teaching you to stretch, or you can find one that rates high on the "woo-woo" factor!
Oh - and search back on some of Denise R.'s posts about her last rotation. She just finished a great rotation that incorporated yoga videos with strength work almost daily and she would be a great person to ask more about learning from videos.
Have fun!
Sophie