I agree with Quark here (I NEVER thought I would say that.....), and I'm not a switcher, I've been using Apple-made computers since 1988.
Just drag the application to the trash, but then run a search from the file menu -> find or press command-f. Type in the name of the program - for the sake of example lets call that program Internet Explorer. With one word names, that's the word you search for. Two word names, it's best to search for what the app usually goes by, if referred to in one word. In our example, this word is 'explorer', because IE defines the program, not the internet itself
So type in 'explorer' in the find box and you see a bunch of crap that just pops up that you never knew you had on your computer. The main file you'll delete would be 'com.microsoft.explorer.plist', or 'com.
company.programname.plist' as these are the preference files the program creates. And in this example, there is also an entire folder dedicated to the program located in the preferences folder. That should also go. And finally, if there is a receipt from the program, such as 'InternetExplorer5.2.3.pkg' or '
name+version.pkg', you can delete that too. This just tells your computer that you have it installed, so you don't accidentally install it again - but if you're deleting it, you won't need that feature.
It also might be easier, before you run a search, to just go to Library -> Preferences and Library -> Receipts and delete these files and the original program, and THEN run a search - there will obviously be fewer results to clutter up the find window.
Does that help - need clarifications?