image from: NirSoft
Now with Windows 7 there aren't nearly as many blue screens as there were in past iterations of windows. But I still occasionally run into them and usually have absolutely no clue what they mean.
While looking around for some information on one of my blue screens I came across a really useful application called BlueScreenView.
This application scans all of the dump files created by windows bluescreens and helps you to figure out what the bluescreen actually means and what might have caused the crash.