The procedure of circumcision:
1. Sterilization: Although the public nature of the ceremony makes complete sterility virtually impossible, the Mohel (ritual circumcision surgeon) does everything in his power to maintain his hands, his instruments and the place of the Berit Mila as clean and sterilized as possible (see here for new recommended standards, by Rabbi Avi Billet)
2. The Magen: The Mohel then places a Magen (shield) on the organ, separating the foreskin from the genital, and protecting the later from the surgical blade. Then the Mohel pronounces the blessing and removes the foreskin with the blade.
Some Mohalim use a clamp, a device which closes on the organ exerting much pressure on it, to attain a virtually bloodless circumcision. The usage of a clamp (Gomco clamp, Mogen Clamp) is medically controversial (see here the FDA recommendations) and is traditionally not accepted in our community.
Other Mohalim do not use any kind of Magen and keep the separation between the organ and the foreskin by hand.
In practice, virtually all orthodox Mohalim use the traditional Magen
3. Peri'ah: The next step is called peri'ah, which means 'uncovering'. It consist of the removal of the inner preputial membrane (epithelium). The Berit Mila is considered done only when this membrane is removed, or permanently peeled back, to uncover the glans. This procedure is done by hand and it is one of the most difficult parts of the performances of the circumcision. Sometimes if this epithelium was not be fully removed by hand, it is necessary to severe the extra skin (tsitisn) by instruments. An expert Mohel recognizes when these extra strips of skin should be removed (me'akebin) and when not.
to be continued...