Maisie,
I live in Inner Richmond and it's quite convenient to travel to other area in San Francisco City. In SF, taking muni is very convenient. Of course, if you drive yourself, you can spend your time more effectively as you don't have to wait for the bus. However, you cannot easily find parking in some of the areas such as Richmond, Sunset, downtown, Chinatown, North Beach...
I don't have any idea about the summer camp because my 2 little ones are too little that they won't need that soon. For places to spend the days with your kids, you can go to Golden Gate Park which is very big and some parts are blocked for pedestrians only during Sundays. There are 2 museums in the park - de Young museum which is an art museum (maybe a bit too boring for kids) and Science museum (but it's now on remodeling and closed). There is a zoo near the beach at the end of Richmond and Sunset area. Another place you can bring your kids to is Exploratorium which is a museum on science and it contains a lot of fun experiments and demonstration of scientific concepts. A lot of schools would arrange school tours for the students. I highly recommend you to bring your kids there. Fisherman's Wharf is a place for sight-seeing and relaxation. You can also visit Ghirardelli Square and enjoy the chocolate and the ice-cream. Seal Rock is nice when the weather is good. Of course, you should bring them for a ride on Cable Car and tour around Lombard Street. I personally would like to visit City Hall and downtown to have a feel of the city too. For libraries, there are quite a bit in the city and there are a few nearby Richmond area.
Since my 2 little ones are so young, we usually like to hang out in Golden Gate Park and let my older one to run around and stroll my little one for a sunbath.
Hope you and the kids enjoy your stay in here.
花旗太太生活在花旗國,留意時差,你問我未必即時答到。