All you have to do is rather simple.
Rearrange all your photos properly on your PC. ( Any name directory any place you want)
See that there are no duplicates.
You may create as many folders as you like with different subjects.
Once you are happy with it. connect the iPAD fire the iTune, and sync the Photos to the iPAD.
Syncing means you point the iTune to the main directories yu have your pictures, and select which one you want to be transfered o the iPAD