If you visit only one museum in Tokyo, make it this one. The Tokyo National Museum's grand buildings hold the world's largest collection of Japanese art, and you could easily spend an entire day perusing the galleries here. The main building offers a walk through Japanese art history from Jomon to Edo Periods on the 2nd floor.
Great history to learn from this place
Spending a morning wandering around the Tokyo National Museum is a great way to get an overview of the cultural history of Japan. While the museum does not go deep on any one area, it does give a number of cultural and religious highlights. There are plenty of english language explanations (for those who can't read Japanesse). Personally, I found the museum layout somewhat confusing. Having started at the side building with the ancient Japan, and then moving to the main building, it took a bit to understand the room layouts. If you have an overview or general understanding of Japanesse culture and their history, you'll enjoy spending the 2 or 3 hours it takes to view the collections.