a new book at amazon that is written for canon speedlite users, has many positive reviews Speedliter's Handbook: Learning to Craft Light with Canon Speedlites
I have this book and it is very very good. ; You can also see Syl on a recent youtube video at B&H where he talks about lighting with speedlites in general http://www.youtube.com/watch?v=OjzbfhbIFd8.
