There are 100+ keyboard shortcuts available for Windows, but there are several you'll want to remember because you'll use them often.
So, while I highly recommend that you take advantage of the free PDF download listing of 100 Windows 8 keyboard shortcuts, I also recommend that you commit the following 10 keyboard shortcuts to memory, because you are going to need to access these features often and, for efficiency's sake, it's best to have them at the ready.
10 Keyboard Shortcuts for Windows 8 you need to remember
The shortcuts for Windows 7
If you have not made the leap to Windows 8, this little cheat sheet will help you work more efficiently with Windows 7.
Note: This list is part of Greg Shultz's comprehensive collection of Windows keyboard shortcuts, available as a PDF download.