Can one depend on Yoga cds and yoga dvds and learn all the yoga techniques properly?
Yoga Videos and Yoga DVD would be useful for those who want to practice yoga at home. Although it is easy to buy a Bikram yoga dvd from most popular stores, and this may give you a great introduction, it would probably be better to join a class. The benefits of joining one of the Bikram yoga classes is there will be people to interact with and even make friends with, also if you have any problems there will be an instructor on hand to help you with any problems.
Dvds & Cds are better.
Always avoid too risky yoga. (even with trainer)