If this is not an employee position - as in this is a sub-contractor opportunity - remember that you are going into business for yourself. Vehicle, fuel, insurance (commercial vehicle liability, general liability, worker's compensation, unemployment), tools, material, uniforms, taxes (local, state, federal, self-employment), state licensure (if any), etc are all your responsibility.
When we contract inexperienced subs we try to talk them out of it by showing all the negative points and see if they are still interested at the end. If so, then we send them out for a half day ride along to see first hand what it is we do. We lose more prospects with the ride along then we do with the initial meeting. The contractor life is not for everyone - nor is running your own small business.
As for training, OJT is probably one of the best ways to get your feet wet. The NSTP certification from the SBCA is good practical technical and legislative info, but frankly I would never send anyone in the field that only had the SBCA cert under their belt. After some OJT and with some construction aptitude then it all comes down to figuring out how it works best for you with the guidelines given. Not every installer does things the same way. Pride in workmanship and treating a customer's home as your own, aesthetically speaking, go a long way.
Wish you good luck!
It sounds so easy. 
