deleting apps and cleaning things up

I am a recent switcher and have noticed alot of "installer packages" and .dmg files on my mac that I don't think I need anymore. Once I move the app to the app folder, can I delete the other items out of my download folder? Also, If I decide I no longer need an app (PS Elements 6.0 for instance...), can I just move it from the app folder to the trash and thats it??? Do I have to do any type of "uninstaller" like I did on the pc? Thanks.

After installing the app you can delete the dmg files. You can also drag the apps to the trash you don't want anymore but there still are remnants left, such as application support. Use AppCleaner to remove files associated with the app.

thank you for the info...time to clean things up and get some hard drive space back!