First off welcome to Mesa, I just got through ground school myself and have really enjoyed it. About a week before you head to PHX you will get an e mail of everything you will need to bring. One of those things is just a typed up list of all the places you have worked in the last 5 years, or maybe it was 10? I don't remember, but you can just turn that in on the first day, which is all paper work and the drug screen anyway. If you have any questions they will help you out with it, it's really not a big deal just as long as they get the information that they want.