Events get a little overhaul in C# 4, Afterward: Effective Events

In Parts I, II, and III, I talked about the slight changes that we made to field like events, to the += and -= event accessor operators, and how this may affect you. Just so we’re all on the same page, I want to consolidate here a list of Dos and Don’ts so you know how to use these language features effectively and safely.

This is a good summary of how to use events in C# 4. Especially good to know if you like to have Warnings As Errors on (which you should).