I found what appears to be a legit and free copy of Sklansky's "Holdem Poker for Advanced Players". It has poker room ads sprinkled through it and an ad at the end from the authors, so I think there are no copyright infringement issues with it. Hmmmm, I guess I can't post url's yet, so PM me, and I'll give you the link. If the moderators think this link is important enough, maybe you can lift my limit, and I'll edit this post to include it.