rookgirl, if you're lucky some of your brakes will have wrench flats on that part that the bolt and the spring go through. If they do you can use cone wrenches to get on that while you tighten bolt. Usually 14 or 15mm.

I just got a bike that doesn't have wrench flats on that part - I gotta get one of those OBW-3s. Or maybe just some different brakes...