How to view all iTunes backups and respective devices? There are a bunch of backups in the folder:

C:\Users\Me\AppData\Roaming\Apple Computer\MobileSync\Backup


However, they're all named gibberish and difficult to identify. This folder takes up 30% of the space on my 500 GB hard drive.

How do I find out what device they're for, along with their date, so I can decide which to delete?
Preferences > Devices will show all backups, from which you can delete specific versions.
On Windows, hit  Alt  to show the menu bar at the top.

This pic from Mac, but should be very similar...