What I want to do is hook up my USB hard drive to this and be able to access it via my appletv. But not sure if I can...is iTunes required for appletv to view movies?

Share your hard drive or printer.
AirPort Time Capsule can turn any external USB hard drive into a secure drive you can share across your Wi-Fi network. So all the documents, videos, photos, and other files instantly become available to anyone, Mac and PC users alike. You can even connect a printer and share it wirelessly.