* The Gemara Kiddushin 29a states that a father is obligated to perform a Brit Milah for his son. Some rishonim assume that the entire obligation on the father is to make sure that the Milah takes place but he doesn't need to personally perform it nor even appoint a Mohel, as long as it is taken care of. These rishonim include the Maharach Or Zaruah (responsa n. 11) and Tosfot Rid (Kiddushin 29a s.v. Otto). However, most rishonim assume that there is an obligation upon the father to actually perform the milah and if he doesn't know how, he should appoint a Mohel to do it for him. These rishonim include the Rambam (Milah 1:1), Darkei Moshe (YD 264:1), and Rosh Chullin 6:8.
* The Ohr Zaruah (v. 2, Siman 107) writes that if the father knows how to do the Milah and nonetheless asks a Mohel to do it for him, he is losing out on his mitzvah. Shach CM 382:4 agrees. The Darkei Moshe 264:1 argues that we always use the principle of agency (Shaliach Adam KeMoto, Kiddushin 41a) and this mitzvah should be no different. The Kesot CM 382:2 defends the Ohr Zaruah saying that Brit Milah is a mitzvah that needs to be done with your body, and can't be delegated to be done by someone else.</ref>
# The father of the baby should place the baby on the lap of the Sandak. <ref>Kitzur Shulchan Aruch 163:1</ref>
# The father of the baby should stand near the Mohel (the one who is performing the circumcision) in order to show that the Mohel is his proxy. <ref>Kitzur Shulchan Aruch 163:1</ref>