Canon has published a PDF: The Quick Guide to Accurate EOS Autofocus. It’s a 2 pager that explains how to use the Autofocus on Canon cameras. It’s not just the the Canon 7D, but also applies to the 5DMk2, 1D serie… I love how they use the word accurate. But the vast majority of the focusing problems are related to the wrong understanding/usage of the autofocus.

The most surprising was the importance of the Viewfinder Diopter Adjustment.

http://www.learn.usa.canon.com/app/pdfs/quickguides/CDLC_Accurate_EOS_AF_QuickGuide.pdf