Design patterns: I wouldn't bother reading the GOF book

I have to disagree with Gil's (welcome to the blogosphere) recommendation regarding the classic DP book:
I found it very hard to read, focusing on theory (as opposed to practice), and laking use of .Net framework features (since it was not written for .Net users).
If you are a .Net programmer and want to learn and use design patterns, I recommend going to dofactory.com - clear, real-world examples meant for C# developers.