First thing, stop in Highland Falls at the West Point Vistor's Center. You can get a lot of good info and history there. If you need a meal there, I highly recommend Schades and Park. two places that we enjoyed many a time while visiting our son:
www.schadesrestaurant.com/parkrest.com/Secondly, go to the museum that is located to the right and behind the visitors center.
When they are at the visitors center they will be told that they have to take the "public tour", which is a bus tour that only stops as a couple of spots, and that they won't be allowed on Post otherwise. Forget that. You can get on post.
Go ahead and proceed to the Thayer gate (the gate that goes in from Highland Falls) and tell them you are there to visit your nephew, who works at the Eisenhower Theater, or you want to go to the Association of Graduates Gift Shop or something like that. Just be firm and sure of yourself and you shouldn't have any problem getting in the gate. You will have to have a photo ID (and unless you are a poor democrat that shouldn't be a problem) and your vehicle will be searched, so be sure you don't have any "assault" weapons or Allybammy moonshine in it anywhere.
Once you get in the gate, you can go pretty much anywhere with the exception of the "Cadet Area", which includes the barracks and cadet courtyards, classrooms, and cadet mess hall.
You can park near Trophy Point (which is a must see, so that works out well), and walk around outside of The Plain (which is the parade grounds that only current Cadets are allowed on) and you can see monuments to Patton (in front of the library), Washington (in front of Washington Hall, believe it or not), MacArthur, Thayer, and others of West Point historical significance. Trophy Point overlooks the Hudson and contains monuments made of weapons from famous battles that the US Army has fought throughout its history.
Fort Putnam is a must see - it is a fort that goes back to the Revolutionary War, in which the West Point of the Hudson River was strategic, thus the name West Point.
Also see the Eisenhower Theater. It is the second largest theater on the East Coast (second only to Radio City Music Hall) and attracts many Broadway shows and major entertainers.
Also next to the Eisenhower Theater is the house that was used as Marty Maher's house in the movie The Long Gray Line.
Also see the Cadet Chapel, which is on the hill behind Washington Hall. You can't miss it and it is an incredible sight both inside and out.
The West Point Cemetery is a good visit. Soldiers dating back to Washington's Continental Army to present are buried there, including many Generals that you will know when you see the stones. Famous Generals like Custer, Westmoreland, Schwartzkopf, Heisman Trophy Winners like Davis, Blanchard, The "Father" of the USMA - Sylvanus Thayer, and others. Must see.
Michie Stadium. It's not all that "impressive" in size by our SEC standards, but it is chocked full of history. Be sure to see it.
The West Point Depository and Mint is also on the Post. They mint silver coins there, and it is a gold bullion storage facility. It is near the Lee Gate, as are the Prep School and the West Point Ski Slope.
A new part of West Point that is worth the visit is the Army Prep School, which used to be at Fort Monmouth, NJ until that Post was closed. The prep school was built on the Post at West Point and opened last year. The Prep School is used primarily for recruited athletes who couldn't get a direct admission to West Point because of academics not being up to West Point standards (The Naval and Air Force Academies have them, too) as a way to get athletes in the back door. As long as the candidate successfully completes the Prep School they get a special (Vice Presidential or Sec. of the Army) appointment to the USMA. It also gives them an opportunity to "redshirt" while still playing games against other prep schools, since the USMA doesn't redshirt players. Cadets are expected to finish and accept commissioning as a 2LT in the Army in 4 years.
Hope this helps. Let me know if you have any other questions.