Of all tools used in construction, the layman is probably most familiar with carpentry tools. There is the claw hammer, the level, the saw, the pencil and, of course, the Band-Aid. As the framing theme song indicates, you will be making frequent use of this last item.
One thing that you have probably not thought much about with regard to your addition is the potential for injury. I'm not talking about the big hospitalization kind of injury; that comes later. I mean the occasional cut and the semi-frequent bruise. On any given day, even if I am not working on a project, I will inevitably cut myself, scrape my knuckles, or puncture myself with a nail.
My wife thinks these injuries are the result of carelessness, masochism, or worse, machismo. Although there is some validity to her notion, I like to think most of my cuts and scrapes are the result of a strong character that allows me to take risks without regard to consequences. This is exhibited in a disdain for pain.
Truthfully, I have found that cuts, or at least scrapes, are not particularly painful. It is when you smash a finger or a toe that you come to know agony. It is no wonder to me that the thumbscrew was one of the most feared implements of torture in the Middle Ages. Personally, I would rather be put in the stocks and have vegetables lobbed at my head than have my thumb crushed. Yet every time I pick up a hammer, I risk that excruciating experience.