Yes to both books and video (for skeet).
I started reading a few books, one by D. Lee Braun, and another by Barney Hartman. Both had some good tips that I was able to add to my game.
I bought a video tape that Todd Bender put out on shooting regular skeet, and I was able to pull a lot from it.
You can read all day about shooting targets, but when you can actually see it being done, it makes a big difference. There are several angles shown, including an 'eye cam' that shows you what you'd see as a shooter. Bender is an excellent instructor, and was able to effectively give a lesson via video tape. He teaches strong basics which I tried to implement into my game.
For skeet I'd highly recommend Bender, I'm sure there must be an equivalent high level instructor for Trap and Sporting as well.
Brad.