I used the one I did because it's the one Zed used for his books (at least that's what it was when I started this one) and since the book is heavily influenced

I used the one I did because it's the one Zed used for his books (at least that's what it was when I started this one) and since the book is heavily influenced by his I wanted to stay in the spirit of Learn X the Hard Way. If this were software I'd probably use a more structured license, but since it's just a book I think this is fine. Worst case: someone doesn't redistribute it because it's not a CC license. Well... they can still read it online...