You're probably more interested in the actual post, housing, etc.
But as a history buff and tourist, It's a pretty cool place to visit. The original post from the 1870s is still there around the parade field. While most of the old cavalry barracks are now (very good) museums, a few of the houses are still occupied by Ft. Sill staff. Unless I am mistaken, the post commander still lives in the old commander's house.
If you know anything about the Red River Wars of 1870s Texas, you'll know that Sill was where the last of the Indian tribes on the southern plains finally came into the reservation. Lots of history there.
They have the Army Field Artillery Museum there, more big guns than you knew even existed.
If you like outdoor stuff, the Wichita Mountains Wildlife Refuge is right next door. And, of course, you have to eat a hamburger at Meers store. Several lakes in the area, and its not terribly far from there to skiing in New Mexico and Colorado. Also a short drive from DFW, if you need the big city.