Just checked at Tivo.com and they now have the user's guides online. They are under service and support, then in the right column click on user's guides.
They have the quick start guide, viewers guide, cablecard installers guide, kidzone guide and HMF guide. I don't know why they have the kidzone guide, I heard that wasn't available yet for the Series3.
I haven't read them yet, but the viewers guide is 146 pages.