Just thought I would point out a great book while I was thinking about it. "Essential C# 3.0: For .NET Framework 3.5, Second Edition", it is a very well written book. Mark Michaelis does a great job of covering a large range of great topics and does a great job of explaining how you do things and why you do things. I've been using it to teach C# to several people and have had great success in using it. I use this book daily as a reference and I always make sure to have it next to me.