Thanks for all of the thoughts/advice.
I will be working for a couple of companies I used to work for, so I know them and what I am getting myself into fairly well. I will own my own software licenses (I already have most that I need) and will be teaching in the evenings while doing the contract work.
Does anyone charge differently when it comes to travel / on site time? For instance, If I have to travel 4 hours to site and stay overnight, work for two days and travel back 4 hours, how would you bill that time? Do you just bill it as another hour of your time, by miles, etc?