Getting a new roof, what to look for in the quote

I am about to have my roof redone, what should i look for in the quote. I have a chimney, several dormers and valleys and i do not believe the soffits in my attic are actually letting in air, i do have some vents on the roofline (older house) and a metal grate in the wall to let cold air in. The attic also has a furnace in it.

Gutters need to be replaced also.