Where can I find movies I have rented, but have yet to download?

Hey Drew30519!

I have an article here that I believe will help you with this question:

How to rent a movie from the iTunes Store on Apple TV

http://support.apple.com/kb/HT1498

You can see all the movies you have rented on the top shelf of the main menu when navigating to Movies. Rented Movies will also indicate when they are due to expire. Once expired, they will no longer be available in your Movies shelf.

If your download is interrupted, go to Setting > iTunes Store and select Check for Rentals. Apple TV will connect with the iTunes Store and will resume downloading.

Thanks for being a part of the Apple Support Communities!

Regards,

Braden