1) hopefully I did not just murder the quote tree
Does he already have editing software he likes? If not, could you get him Lightroom or Photoshop?
He does - I've suggested Photoshop before but he doesn't think he'll ever learn to use it fully.
2) depending on your budget, and his interest, (and I guess your location) would Photoshop + a Photoshop class be an idea? My dad has been using Photoshop for a while, and takes classes sometimes still. He's in a fairly large city, so I don't know how common the classes are elsewhere.
I'll run that by him before I fork out. I've offered him photography classes before and he's turned them down because he doesn't want to "deal with people" (he's really not as miserable as that makes him sound, honest!)
Does he have a camera bag he likes? Or maybe one of those photographer's vests with all the pockets plus some memory cards for the camera? Is there another lens he might like? Or a backup drive for storing photos?
Just as a general thing, before gift-giving occasions, my DH and I have a system. We go to places we like to shop, and will take turns dropping "hints" of things we'd like. The other person is always free to get something not on the list, but at least it gives us a place to start. And since we give more hints than we actually get gifts for each other, some of the element of surprise is still there.