Here you can see my brother and me working the hive. There are different methods to adding a brood box, but I chose pyramiding (let me know in the comments when and how you add new boxes to the hive). Imagine the broodnest as a pyramid in the center of the boxes, with the honey frames lining the outside. That is what I'm trying to do. It is a pretty basic process, just move the three center frames from the bottom to the three center slots in the top box. Push the remaining frames in the bottom to the center, then add empty frames to the outside.
This is my hive after I added the second box. I think that it looks really nice (except for the smudge of wax in the center, but hey, that gives it character). Be careful when you add a new box. If you add it too early, you run the risk of demoralizing the bees. Demoralizing is when there is so much empty room in the hive that the bees don't even think its possible to fill all the frames. Why attempt an impossible task? Demoralizing the bees will cause them to build slower, this will hold your beehive back. That is a concept I learned from "The Fat Bee Man" on youtube. He is very experienced and gives great tips.