This is a small community, with a two block preserved historic district that features buildings from the late 1800's. These retail stores are still active and locals shop there. In the middle is a Folsom museum which is open Wed-Sun 10-5PM and admission is $5; maybe takes 1/2 to tour the displays. Around the old district is new mall and shopping centers, and neighborhoods for 10-12 miles west and south before you can get back to US 80.
Just up highway 50 a bit is Folsom Lake. It is a wonderful place to go with your family for a picnic in a quiet private cove. It is also a great place to go with 10 of your friends, 5 coolers of beer, a wave runner, a Mastercraft and a wake board or water ski. Folsom is the summer playgroaund for Sacramentonians, a perfect place to get into the water and out of the heat. If you don't have a boat and your not satisfied with hanging out on the shore, you can rent one here. http://www.folsomlakerentals.com/
Small but surprising nice little zoo in Folsom city park. The admission is reasonable and the collection good for a little zoo. Definitely not worth going out of the way for but worth a peak if your in the area.
Folsom Lake is northern California's most popular fresh-water lake. A great place for water sports, hiking, and picnicing. The dam is off-limits now, for security reasons.
Folsom, a suburb of Sacramento, has a huge artificial lake and an infamous prison. The American River flows out below Folsom Dam, and down to Sacramento. A nice day trip from Sacramento.