We had a leak in the roof valley (between our sun room and the main house) which seemed to be getting worse.
I did a Google search for roofing contractors in my area. To me, the most important considerations were finding someone local, seeing good reviews from previous customers, and how the contractor came across on the telephone (i.e. did he/she ask the right questions, suggest possible causes, etc.).
The contractor I eventually hired asked some relevant questions and surmised that the cause of the leak probably was the roof valley or unsealed nail holes in the roof shingles. He was very professional and did not try to upsell me.
His crew showed up on time and cleaned up after themselves when they were finished. The repair took about 6 to 7 hours altogether and I am quite happy with the results. Mike and his crew were very professional.
If you are a homeowner looking to hire someone for a roof repair, I advise you: Always get the contractor to come out to inspect the issue, then to talk you through the exact repair steps and to give you the cost of the repair in writing. These are all things that Mike Yarkey did for me.