S.G.
I used to live in Claremont. I live in Rancho Cucamonga now. It is a GREAT area. Be sure and check out the parks & recreation guide that Claremont puts out (http://www.ci.claremont.ca.us/index.cfm) as well as surrounding cities for lots of classes, activities and more.
There are lots of day trip ideas here: http://www.daytrippen.com/inland.html
Claremont has lots of lovely parks. The Claremont Hills Wilderness Park is a great park to go on a walk or long hike. During the summer, Memorial Park has a small water splash pool, plus movies & concerts - all free. Downtown Upland and Claremont both have cute areas to walk around and shop and eat.
Good luck and have fun!