Check out this video from Canon and Syl Arena as he walks us through the on-camera menu system for controlling Canon Speedlites like the 600EX-RT.
Syl is the author of the popular Speedliter’s Handbook series, which is now in its second edition. If you are interested in really digging into the Canon Speedlite system to understand how it works, his book is well worth the money. You can read my review of the first edition here.