Remember that scene in Star Wars when Luke (or was it Han Solo?) cuts open that crazy goat-beast thing’s belly and slides inside for life-giving warmth? Well the .NET guys have done the same today by making the .NET Framework Library source code available for nerdly enjoyment.
When I was learning CodeGear’s Delphi (still the best tool for creating native Win32 apps I must say) having the complete source to the VCL (the Delphi framework) was the best learning tool I could have asked for. Whenever I was unsure of how to code up a certain pattern I went trolling through the source and found inspiration. Sometimes I just browsed it for fun and other times it was a life-saver when it came to debugging and tracking down hard to find issues.
Even if you don’t think you’ll use it for debugging download it anyway and just browse the developer comments to see how the crew aboard a big ship like Microsoft treats their code.