One thing is for certain and that is that all roofs ever need to be replaced and that means that at some point in every homeowners life they are going to have to deal with a roofing contractor. You should ask around and see if your friends and coworkers have one that they can recommend and then take bids from the three or four names that you have gathered.
They will all base their bids off of a set going price that is awaiting in the area that you live, so they all should be pretty close together. However; the devil is in the details when it comes to roofing a home, so there are a few things that you will want to get nailed down specifically.
For instance; you will want to know if replacing the metal such as valleys and roof jacks is included in the price of the job. Also, you will want to know specifically how soon the roof will be replaced after the old roof is torn off, so your are not left worrying about the weather with no roof on your home.
You are going to also want to know how much the roofing contractor charges by the "man hour" for any dry rot repair that will have to be done. Also, you are going g to want to make sure that the contractor is going to make right any damage that is done to your landscaping or home while the job is being done.
Do not be shy about making up your own quick contract to cover all of these issues, because the contractors contract most likely will not have these items included in it. Make it a simple easy to understand contract that includes such details as touching up scuffed up fascia board and repairing damaged gutters.