Hi, John.
Is it supposed to be a guide, or an issue? :) Zico's videos don't bother with AD specifically, as, as long as CR/oxAuth cares, AD in no way more special than other directories. You provide ports to connect, binding credentials, DNs to search for users beneath of, and key attribute you will use (which supposed to be unique amongst all entries you'll be pulling in). But actually there is a guide specifically for AD, written by me long before. I've seen somebody provided a link to pdf with it before, though not sure is there a link to it in docs.
Why do you think we need a guide just for AD, have you encountered any difficulties while configuring it, which you haven't with other LDAP directories?