- Control versus Command (Apple). In Windows, most of the Ctrl key combinations are substituted by Apple-. Example, Ctrl-C in Windows (Copy) is Apple-C in Mac OSX. Ctrl-V in Windows (Paste) is Apple-V in Mac OSX. The MacBook also has a Ctrl button but it works mostly for navigation (so far, that's my observation).
- Ctrl-Alt-Del vs. Apple-Option-Esc. To kill misbehaving tasks in Mac, just press Apple-Option-Esc. This brings out the Force Quit window which will easily kill the erring application. In Windows, bringing out the kill window either brings down my whole system or makes me wait forever (sometimes both, and not in that order). So far, Mac has recovered gracefully from force quits.
- Alt-Tab vs Expose. In Mac OSX, Alt-Tab (switch between applications) is Apple-Tab. But Mac has a neat feature called Expose, which is difficult to appreciate by Windows users. In Windows, your only choice to find an open application is to either Alt-Tab or hover your mouse over the task bar tabs. In Mac OSX, just activate Expose by pressing F9. This zooms out all open windows and creates miniature windows that you can choose from. It's the equivalent of getting a bird's eye view of all your active screens. Presenting them visually makes it easier for you to choose what you are looking for. In Windows, the closest equivalent is to press Windows-M, which hides all windows. Then you have to Alt-Tab each of them to choose. Or hover the mouse over each minimized instance -- which is like working on a text-based world since your only clue to window contents is the title, which can sometimes contain a very long string of text.
Mac OSX - Windows OS translation
One important transition to make when switching is to keep a side by side comparison of Windows and Mac OSX commands and applications. Here's a general comparison. I'll be adding to this list as I go along making discoveries: