This might be a good moment to mention that Chaturanga and Upwards-Facing Dog can both be tough on the wrists, so it's a good idea to start paying attention to how you bear weight through your hands now in order to avoid injury, especially if you're prone to carpal tunnel syndrome.

Yoga Journal has a useful article, Hands Down. And in iTunes, My Yoga Online have a little six-minute demonstration, Wrist Safety in Yoga, which seems like it has a lot of valuable information.

ETA: I hope you don't mind me linkbombing you -- I'm just full of yoga squee right now *g*.