Here are some common keyboard shortcuts that will work in many programs. Once you become familiar with these keyboard shortcuts, you will be more productive and more computer literate.

CTRL+S: Save

CTRL+O: Open

CTRL+N: New File

ALT+F4: Close Window/Program

F3/CTRL+G: Find

CTRL+A: Select All

CTRL+C: Copy

CTRL+X: Cut

CTRL+V: Paste

CTRL+Z: Undo

CTRL+Y: Redo

CTRL+B: Bold

CTRL+U: Underline

CTRL+I: Italic

Here is a great article that outlines all of the keyboard shortcuts across all OS'.