Below is a list of miscellaneous computer tips that could improve your productivity when using your computer. When some of my tips are different on the Mac versus PC, I will provide you separate comments about each. For any of my suggestions, you can find out more by "Googling" them.
Microsoft Windows and Mac OS X each provide "toolbars" positioned at the bottom of your computer monitor. I have always questioned this position because most computer screens have less vertical pixels than horizontal pixels, and it therefore didn't make sense to me to "give up" some of my more precious vertical space to the toolbar. Therefore, on both my PC's (since Windows 95) and on my Mac I move my toolbar to the left. Yes, one can also make it so that these toolbars auto-hide, but I don't prefer this because I do like the ability to quickly use ICON on the toolbar.
I prefer keeping my desktop clean, and free of files. This goes against many user's view of the desktop, who tend to place many files, both temporary and most needed, on the desktop. I prefer putting my temporary and "work-in-process" files into their own folders, and not on the desktop.
Since Windows 7, Microsoft has provided a quick way to start applications that you "dock" on the toolbar. The keystroke is Windows-1, Windows-2, etc., and they start the application "docked" in the first, second, third, etc. positions respectively.
On the PC: Alt-F4. On the Mac: Command-Q.
Although "My Documents" has been provided by both Microsoft and Apple, I don't like using it because many applications automatically want to using this folder for their own applications. Instead, I prefer making my own folder for my own documents.
Open up your "filing" system: (PC) Windows-E: Brings up your filing system (Explorer). (Mac) No equivalent keystroke. I use a utility called "BetterTouchTool" (see note below).
Minimize all Windows: (PC) Windows-M. (Mac) No equivalent keystroke, however, command-M will minimize the current window.
Cut/Copy/Paste: ctrl-x, ctrl-c, ctrl-v. I believe that I first saw these keystrokes on the first Macintosh computer and that later, when MS Windows 3.1 became success, Microsoft also adopted these same keystroke for Windows. These keystrokes remain the de facto standard for most modern software products (not just Office).
ctrl-b: Bold. ctrl-i: Italicize. ctrl-u: underline.
ctrl-z: Undo
On the PC: Either Windows-Tab, or Alt-Tab. On the Mac, Command-Tab.
On the PC: Windows-left arrow, Windows-right arrow. On the Mac, I use BetterTouchTool (see below).
ctrl-Y: Repeat what I did last. (Works in Word, too.)
shift-space: Select row. ctrl-space: Select column.
ctrl-": Duplicates contents from above (command-" Mac).
Some Navigation Shortcuts for various versions of Excel.
ctrl-t (PC), command-t (Mac): Provides another window, or sheet, within the same browser window.
To get another "instance" of a browser window: On the PC, shift-click on the browser icon on the toolbar. On the Mac, command-N (for new).
Coming soon.
Calculations very easily done.
TotalCommander (PC): A better file management utility than Explorer.
BetterTouchTool (Mac, Free): Provides you the "power" to redefine keystrokes, mouse buttons, and much more. I have set up my BetterTouchTool to provide many of the Windows 7 shortcuts that I liked. Doing so, actually provides a better solution than what Microsoft provided.
Here are my current BetterTouchTool keyboard definitions. Right now, I like using the Mac's "option" key for most of the definitions.