i dont really know what this means:

Enter the prefix you wish to match other user partitions with.

Examples: home matches /home, /home2, /newhome, /anythingwithhomeinit/


what should that be?

what ever you would like it :)
For simplicity's sake just using /home is fine. It just means that a user's path for theDomain directory is /home/username/public_html. If you used myhome it would be /myhome/username/public_html.

Hope that helps

agreed with cweb that using /home would save a lot of memory work from your brain. haha.