Photo File Organizer is a program that truly will organize and clean up your photo collection. The main function of this program is to rename your photo files based on the date the photo was taken and the camera manufacturer/model. It searches for photo files in the folder of your choice and renames and copy/move the photos to your desired location.
This will help you get your entire photo collection in one place. It will also remove duplicates. And best of all, your photos will be sorted based on when the photo was taken. The program even has a test-mode that will show you what will happen before you choose to actually do it.