Nothing gets you excited about this year’s WordCamp like watching videos from past years’ WordCamp. Watch WordPress.tv videos from WordCamp Portland 2012, 2011, 2010, 2009 and 2008 (ok, those are just slides but still).
Some highlights for us (in chronological order):
Grant Landram: How to Build a Professional WordPress Business
John Hawkins: Intro to Child Themes
Mark Jaquith: SWAN DIVE! …into the Best WordPress of your Life
Michael Fields: New and Exciting Ways to Organize Your WordPress Powered Website