Visual QuickStart books online
Access to 25 books for $49.95 a year. That's a hell of a good deal. I buy a lot of books that I don't immediately need... books that I know I'll need eventually as a reference, kind of an information insurance policy. If I need one piece of information quickly, and finding it in 5 minutes in a book I have on my shelf will save me 4 or more hours of search elsewhere, it's easily worth the price of the book.
So, $49.95 for 25 insurance policies (of which I'll probably only need 5 a year) is a pretty good deal for me.