Today I was helping my father with his computer and used several keyboard shortcuts in the process. These are commonly used but he didn't know them, so I figured some people on PC know them, whereas others can refer to this thread. These are the ones I know but there probably are many, many more! Keep in mind, if you're using Unix/Linux or Apple, then these shortcuts will be different.

Shortcuts for Internet browsers

* = if you're using a forum, such as PC, make sure the text area where you type in is not selected.

Add bookmark: CTRL + D
Moving forward between tabs: CTRL + Tab OR CTRL + PageUp
Moving to previous tab: CTRL + Shift + Tab OR CTRL + PageDown
View browsing history: CTRL + H
Refresh page: CTRL + R
*Go to previous page: Delete
Open new tab: CTRL + T
Close window: CTRL + W
Close tab: CTRL + W
Quit the program: CTRL + Q
Zoom in: CTRL + + (CTRL and +)
Zoom out: CTRL + - (CTRL and -)
Print: CTRL + P
New window: CTRL + N
Select all: CTRL + A

MS Processor or other applications

** = I've found only a few times I use this, most commonly when I'm archiving a file(s) into a .zip or .rar through IZArk (or WinZip or WinRar), the archived file may not show right away.

Select all: CTRL + A
Change font: CTRL + D
Larger font size: CTRL + Shift + < OR CTRL + ]
Small font size: CTRL + Shift + > OR CTRL + [
Underline: CTRL + U
Bold: CTRL + B
Italicize: CTRL + I
Print: CTRL + P
Undo: CTRL + Z
Save: CTRL + S
Save as: CTRL + Shift + S
Change paragraph alignment: CTRL + R
Change margin: CTRL + T
Change between application windows: Windows + Tab OR Alt + Tab (hold down either Windows or Alt and press Tab to change between the windows, then once you found the desired application, let go of both buttons)
Superscript: Ctrl + Shift + =
Subscript: CTRL + Shift + + OR do the shortcut for superscript twice
Go to: CTRL + G
Find: CTRL + F
Replace: CTRL + H
Increase spacing between lines: CTRL + @ (CTRL + 2 will not do this)
Decrease spacing between lines: CTRL + ! (CTRL + 1 will not do this)
Get shortcuts to scroll between menus: Alt (there will be letter keys above each menu)
Go to task manager: CTRL + Alt + Del
**Refresh in Windows Explorer: F5
Print preview: CTRL + Alt + I
Make a new page in MS Word: CTRL + Enter
Preferences: CTRL + ; (this does not work in any Word processor but may work in other applications, such as Dr.Java and possibly Eclipse)