I notice that apps downloaded through the Mac App Store are placed in the /Applications folder on my Mac. Is there any special procedure to delete them, or can I just drag them to the trash like I can with other apps?
If you have Lion, then you can also hold down the option key in Launchpad; the icons will start to wiggle and show little x's on all the App Store installed apps very much like iOS does. Click the x and confirm the deletion and it will be the equivalent of dragging it to the trash from Finder; which means supporting preference files, etc. still remain, but for most users that should be of no concern.
There's no delete mechanism in the App Store. You can use a normal app-removal procedure to get rid of it. Apps leave config information and what not lying around that's outside of the .app container, so just dragging the .app container to the trash doesn't uninstall it completely. An uninstaller app like TrashMe will find and remove most of the little bits apps strew about your profile.