Red Gate Crib Sheet Compendium
Red Gate has compiled a bunch of it's Cribsheets into a single E-book, the SQL Server Cribsheet Compendium. It's pretty cool. I've got two entries in there, performance tuning and backups & restores, along with great articles from Robyn Page, Phil Factor, Robert Sheldon and Amirthalingam Prasanna, pretty heady company. It's worth a look.