Reddit reviews Insight Yoga: An Innovative Synthesis of Traditional Yoga, Meditation, and Eastern Approaches to Healing and Well-Being

I don't have a lot of natural flexibility. Probably more than you, OP, but still not a lot.

For legs I do the routine outlined in Yin Yoga and also in Insight Yoga, including the dragon pose and other hip stretches. Paul Grilley also has a good DVD on Yin Yoga.

My general method has been to read books and go from there. Toe touches are good in also helping you develop flexibility in your spine and back. Don't be discouraged if you are only able to do three or four stretches in a book. That is a good place to start. The components of the body are connected so as you continue to practice you'll become able to do more stretches. For instance by loosening your back muscles you'll be able to do that hip stretch you could never get before. Try to do the stretches that you feel a good stretch in and are for areas of your body you prioritize. Even if you do only two or three stretches a day that is a good place to start.

edit: Mth25 named some of the same poses I have found effective for stretching my legs and hips. Just try googling those to get an idea. There's a lot of similarity between the various teachers so it's just about matching what they teach with what you're capable of and feel a stretch in.