I didn't even really learn from a book, much less a class or video. I bought myself one of the student kits about three years ago, played around with it for a while, got bored and shoved it into the back of a closet... but now I'm back with a vengeance, baby! (Just ask my fiance, I'm driving him nuts with my cake habit.)
I've got several things in my collection... my suggestion is to buy the course books, and don't worry about the practice board if you've been thinking about it. The pages that come with the practice board are also printed in the back of the course books; just copy them (if you don't want to cut them out of the books) and slide them into page protectors. Works much better than the practice board.
I would also recommend, if you can find them for a price that you feel is reasonable, to get the 3 volumes of the 1970's Wilton Way encyclopedias. You may not be interested in anything but Vol 3 at the moment - tips, flowers, recipes in the back, cake directions - but you may want #1 eventually. #2 is on its way to me at the moment, so I can't suggest it either way. I laid out $96 for my three books, and during the lean spell on ebay a few weeks ago when I bought them, that was *cheap*.
Devour pictures like it's an addiction. Seriously. I've spent about 60-80 hours in the past two weeks finding pictures of cakes, not just for composition, but for tip use examples. It's helped a huge amount, because I have the photo resources now to check what I'm doing against examples from every skill level there is.
I personally, at the point where I am now, justify spending the money for classes. Between the course books and the online forums, I don't think there's a single thing that they could teach me that I don't already know. Practice, on the other hand...
Sorry for being so wordy... bad habit of mine.