I plan on reroofing my home it has only one layer of shingles on it now. what is the best way 2 start thisjob?

If you don't know how to do it, or you have no one that could help you that knows how to do it, you need to hire someone that does it for a living or knows how to do it well. This is one of the most important areas of your home, because if it leaks, it will cause a lot of damage that will be very expensive to fix.In the long run you would not be saving anything by doing it yourself if it is not done right. Good luck!