No need for uninstallers on the Mac. Just drag what you don't want to the Trash. Applications are usually self-contained except for a single plist file left in your Preferences folder. In the case that a program scatters its support files in other places, it usually comes with an uninstaller of some sort.
The Help menu in your menubar can be pretty useful when you're looking for a particular function. If you want something with more substance, David Pogue's Missing Manual
series is known to be extremely helpful.