Yoga

Ashtanga yoga: http://www.ashtanga.com/

Pranayama
The Pranayama Institute: http://www.pranayama.org/
Shivananda Yoga - proper breathing: http://www.sivananda.org/breathin.htm
Introduction to Pranayama and Yogic Breathing: http://www.yogasite.com/pranayama.htm

Meditation
Links on meditation: http://indiafocus.indiainfo.com/society_and_culture/religions/hinduism/meditation/