Snap is a good video. its an instructional and it takes you through getting started and getting up and then into tricks for progression...its a lot like The Book but i thought The Book was pretty cheesy, i recommend Snap.
Both Snap and the book are good instructional vids, Book certainly gets much more detailed. If you have a short attention span like myself and do not find it helpeful to see tricks related to skateboarding you would be better off with Snap.
If you can get up on a wakeboard, its basically the same thing- just let the board float and plop your feet on it and when the boat idles the water pressure will press it into your feet like a wakeboard. Everything else is pretty much the same.