Jim Morse has a "Crib sheet" that he has compiled from PI Forum posts and other sources that has lots of useful info. If you're interested, PM me your email address and I'll send you the latest version and ask him to add you to his mailing list.
I think Warren's book is very useful for explaining how the basic processes and scripts work. Perhaps he's planning a sequel that delves more into high level workflow and advanced topics. I'll ask him
Cheers,
Rick.