Take Control of Upgrading to Lion Joe Kissell
Joe Kissell’s book is hands down the best guide I’ve seen to upgrading to Lion. He takes you through the questions you need to answer before upgrading, downloading the installer and 
backing up, as well as the install process itself. Take Control of Upgrading Lion covers how to determine if your hardware is ready for the Lion upgrade, if you’re Rosetta dependency-free, even how to purge your drive of duplicates and archaic leftovers from previous versions of OS X. Perhaps most importantly, Kissell includes an especially helpful section on the initial configuration steps you need to take once you’ve done a basic OS X Lion install.
Perhaps most helpful of all, Kissel even covers Apple’s new built in Recovery mode if you need to re-install Lion.
I used Take Control of Upgrading to Lion before, during, and after my own Lion upgrade; it was exceedingly helpful. The one change I’d suggest is perhaps adding a note about moving or copying the Lion Installer before beginning the install to the Quick Start page.
You can read the table of contents and the introduction to Take Control of Upgrading to Lion.