If you or someone you know would like to have additional safety and riding instructions, every Saturday the Orange County Wheelmen holds a free "ride like a pro" class near John Wayne Airport. 

Bicycle Club of Irvine (BCI) also offers periodic classes for new riders.  The next one is on December 1, 2012. Here's a link to BCI's webpage:  BCI NewB Rides - Look for Dec 01, and the flyer discussing the rides is located here:  Flyer.