Try 'man defaults' from the terminal for more info. Also you can use the command line 'defaults' command. You can use the utility app Property List Editor to modify plists (which are basically just XML files with key/value pairs). There are a few ways to modify these settings by hand, but tread with similar care as you would before modifying the Windows Registry (though at worst you would break only a specific app and not the entire OS).

Generally these things are modified through the applications GUI, most Apple apps have a Preferences menu. The common place for finding these things are ~/Library/Preferences Applications will also store user specific data/settings in ~/Library/Application Support To save preferences and the like for a given application and users, things called property lists are used (plist is the extension for these files). To delete, you just delete it in the Applications folder. To install, you just drag the app to the Applications folder. Applications themselves are self contained bundles, which at the low-level are really a folder with all the things the app needs to run. Apple does not have a registry like Windows, much to most users glee.

For apple instal Total Registry 0.9.7.5