Hi A.,
Yoga is going to be awesome for you!
I've been a yoga instructor for 14 years now and it does me wonders as I know it will do for you also.
Yoga does not have to be done in 100 degree temperature room. Please set your room/house temp to what your comfortable with.
For resources, even Walmart & Target sell yoga DVDs & VHSs. A good resource on-line is www.yogajournal.com. Yoga Journal also has a magazine to view.
The main thing with yoga is to do it at your body's comfort-level. Never force a pose or posture. If you feel pain during a pose or posture, back out of it slightly. If pain persists, stop the pose all-together. Pain is not good. Stay well hydrated always. Drink water before, during and after your yoga sessions.
I wish you well with your yoga journey A..
Namaste,
D. P., LMT, CPT
Licensed Massage Therapist
Certified Personal Trainer
Physical Therapy Rehab Tech
Birth Doula