What is a Mohel?
A Mohel is essentially a doctor who specializes in circumcision. He has the medical knowledge and expertise in performing circumcision in a non-hospital setting, keeping up with the highest standards of safety and sterilization. Many prefer a Mohel over a doctor because of his specific experience with circumcisions. A Mohel also usually checks the babies health before the Bris Milah and checks up on the baby (and parents) post-Bris.
Besides for the actual procedure, a Mohel is a rabbi who knows the ins-and-outs of a proper kosher Bris. He can graciously lead the ceremony that brings another Jewish boy into the Covenant of Abraham.