I have started a video tutorial series around UV mapping. The first part is 11 short videos long, and explains the different mapping methods. It also includes a short video that explains how to add a checker texture when you map with Cycles renderer.
The tutorial series can be found directly in the Youtube Playlist: www.youtube.com/watch?v=GhaFQvDxvt4&list=PLB0iqEbIPQTYju1sZkTlTcFDtnCMGYzpN