Here are a couple of photos to give you an idea. They were taken a while ago, and since then the tracks facilities have been uprgaded somewhat and there is a central tower/viewing platform that gives a birds eye view of the entire track.
This photo was taken from the upper edge of the track at the highest point. The main straight leading up the hill is to the right of the frame.
The pit area. The track is popular with drifting and bikes.
Another view of the pit area and the bottom corner.
Getting there is pretty straight forward, get off the Chuo at NIRASAKI, turn right after the toll boths and stay on that road. It goes up into the mountains and through a couple of small villages. Keep going straight. There are no stop signals or anything like that. The entrance is quite narrow but there is a large YOKOHAMA tires signboard to let you know when to turn.
There isn't much else around there, except for some OK mountain roads that are usually deserted. The nearest 7/11 is the one you'll pass after turnning right from the toll booths. If you turn left and decend the hill there is an Autobacs in Niraski town along with McDonalds, but that's about it.
Aki the track is quite technical and it driving it will certainly help build driving skills, which is what the day is about. With the exception of the short main straight it is all either inclined or declining turns. You won't be able to get to any of the speeds possible on tracks like Fuji or even Tsukuba for that matter, but you will be able to test your GTR's cornering and braking ability.