DanGir, the bus tour is actually really informative and worthwhile- I'm not normally a bus tour kind of gal but I liked this one enough to do it on two separate occasions! There are some other cool things to do while you are there: visitor's center is interesting, as is the WP museum. All are right outside Thayer Gate. The Thayer is a nice place for a meal- outside in the good weather, and brunch is especially good.
There are a couple of other options for visiting on post. During the summer there are concerts that are open to the public at Trophy Point. Check me on this- I think they occur on July 4 (with fireworks over the river) and on most Sunday evenings. And during the school year you can schedule a day visit with Admissions. This includes time shadowing a cadet for your child and a cadet-led tour for parents, siblings, etc.
Despite living hundreds of miles away we have visited multiple times and learned new things, taken more in each time. Do it!