+1. The Bob Mannel book has been an excellent resource, and describes many of the hipo features in regards to the motor. Accurately as far as I have found.
+1 on the hipo site as well. I gleaned a lot of info off there, and Fred Ballard (one of the moderators) is an excellent hipo resource, although the site activity has decreased.
As far as books vs forums, each have their place IMO, and the books are invaluable. Especially for someone who is learning from the ground up. I have gotten the majority of my info from Bob's, Tony's, and other books. Then I use the forums to correct errors, keep up to date, and research unknowns. This forum has been invaluable for that.
The books are better organized for sitting down and learning in bulk, and for use as a reference IMO. I can't imagine having to ask endless questions or use search to learn everything I have learned. Some of the book info can be incorrect or get out of date, but the percentage is usually low in my experience.
+1 a new Hipo book would be great.
Even a corrected and expanded one from Tony Gregory.