Mac users can switch between open applications by pressing Cmnd+ ~ (tilde) but the problem with this is that you have to have an application running in the foreground. Another option is to use a program called Witch, which lets you switch between all the opened windows by pressing a shortcut and choosing from an arranged list of windows titles. You can also use the Expose feature by pressing F9 to see thumbnails of all of your open windows, and you can then just click on the want you to be in the forefront, and the Spaces feature allows for multiple desktops of different windows. Spaces is configured under the System Preferences > Expose and Spaces.
New Mac users who have come from Windows might get disappointed because they can not use shortcuts to open the menus like they could do in Windows. For example in Windows, Alt+F gets you to the File menu, Alt-T to tools menu and so on. There is no such thing in Mac but there is something different that too lets you open menus using keyboard. It is Control + F2 and when you press it, the Apple menu gets highlighted and you can navigate through other menus with the arrow keys on your keyboard.
Mac provides a very easy and quick way to create slideshow on your Mac, without needing to go to iPhoto, you can do it straight from Finder instead. To do this, simply navigate to the folder containing pictures and select the pictures (press Cmnd-A to select all pictures or to select individual pictures, hold down Cmnd and select the pictures you want to view) you want to view in the slideshow. Now right-click then select Slideshow from the contextual menu and the slideshow opens in full screen mode with photos changing photos every 3 seconds
There are tons of cool icons available for Mac out there, like at here. You can replace the default icons of your files, folders and applications in a few simple steps
1- Download the icons of your choice from any website.
2- Open Finder then go to Applications and locate the file, folder or application you want to change icon of.
3- If you are wanting to change icon of Firefox, for example, then right-click on its icon and select Get Info
4- A window will open, leave it open and go back the desktop and right-click on the icon you downloaded and select Copy.
5- Go back to the opened window and select the Firefox icon with a single left-click.
6- Finally, paste your new icon by simply pressing Cmnd-V together
7- Your Firefox icon is now changed.
In Mac OS X, the energy-saving options are enabled by default. This is not always a problem but if you get tired of your display dimming every few minutes, you can change the energy settings. To do this, select System Preferences from the Apple menu then click on Energy Saver. Drag the pointer under “put display to sleep when the computer is inactive” to whatever time that you will be comfortable with. Now go the Options tab and uncheck the “Automatically reduce brightness of the display before display sleep” box.