Are you confused by all of the talk about functional programming going on in
the world of C# these days? If so, maybe it's time to play a little catch up.
There are a lot of resources available that you can go to but the most
valuable that I've found are the video lectures by
Hal Abelson and
Gerald Jay Sussman
from MIT's
Structure and Interpretation of Computer Programs course. These lectures
were given in 1986 and may look a bit dated (I saw one guy in the class that
looks like "Rusty" from "National Lampoon's Vacation") but the content is
fantastic.
You can download the video lectures
here.