In an overwhelming majority of cases, applications for Mac OS X can be installed and uninstalled by the "drag and drop" procedure. The latter consists of simply dragging the application itself (or its parent folder) to the Trash. Yes, it's really that easy!
You can also remove support files and settings files for the application located in the top-level Library folder and your home Library folder, but this is not necessary. Those files only store preferences and support files for the applications and will remain completely inert when the application is not running.
There is also nothing directly analogous to the Windows registry in Mac OS X that needs to be edited to make or break applications.
See Uninstalling Mac OS X Apps
for more details.