Pinterest is a great place for finding many different cornrow styles. Pinterest allows you to make virtual boards where you can "pin" or bookmark things that spark your interest so that you have it saved for further reference. You can make your own or follow boards like Cornrows to find different hairstyles you like.
Tumblr is another place to check out if you want to see photos of people with cornrows. To get inspiration for your next do, even if you don't want to join Tumblr, you can still see pictures from people who have tagged their photos "cornrows".