Plenty of advice regarding gear already. If you want some good basic videos about fly fishing specific species, go to the Orvis website and check out their videos. They were the ones that were aired on WFN as episodes of Orvis Guide to Flyfishing. Each video also includes flycasting instruction. It would also be really helpful if you can get out with someone who has some experience.
Have fun.
http://howtoflyfish.orvis.com/