This is how I put them together. I had some scrap plywood that I just screwed the sockets to and then wired the lights together. That is my dog, samson, in the last picture. He likes to support me in my endeavors.
This is the fixture lit up over my tank. As you can see the lights are not hanging straight. It took me forever to get it at this point so if it really bugs me I will end up straightening up the lights.