I was very impressed by this museum. I thought that it would be boring, but thanks to lively displays and lifelike homes, fields, etc, it was actually a very interesting museum. They even grow a few crops outside the museum in a small plot. Thanks to numerous dioramas, I think that children would enjoy this museum as well.
The museum does an excellent job of showing what a Korean farmer's life would have been like before modern times. I have been to almost all of the major museums here in Seoul, and this was definitely one of the best ones, especially if you are interested in more than just the royalty.
Most of the exhibits are in Korean and English.
It takes about an hour to go through the 1st and 2nd floors if you read all the signs. There is also a display in the basement, which is on current Korean agricultural products and farmer associations, but if you are pressed for time you could skip the bottom floor.