I'm a big fan of reading code, so I'll encourage you to start now and never stop. Are you looking for anything in particular? Particular technologies or business domains?
There are vast amounts of open source Java out there. I guess it's as "real world" as it gets, and varies in quality as much as code on any planet. The
Jakarta Commons probably has a good body of things in small enough bites to understand.
[ September 18, 2006: Message edited by: Stan James ]