This is a rough outline of what's necessary. Mileage may vary, but it should give you a solid starting point for study.
The LDAP source doesn't matter. In your case, it's Active Directory. All that matters is that your user and group objects are populated with the correct RFC2307 attributes. RFC2307 defines the standard LDAP attributes for each user and group object that will correspond to the fields in /etc/passwd, /etc/shadow, and /etc/group. When your Linux servers go to look up a user or group, it will assume these specific attributes are populated when it runs its queries.
Depending on your distribution and how old it is, you'll likely be using nss_ldap or nss-pam-ldapd. These libraries are what PAM is going to use to actually make its LDAP queries. Those configuration files are where you'll specify the AD servers, the user/group OUs and filters, attribute mappings (if needed), etc.
Finally, you'll need to actually tell Linux to use LDAP as one of its sources of user and group information. This is handled by /etc/nsswitch.conf. This file is simple mapping of database to information source. In your case, you'll just want to add "ldap" to the lists for the "passwd", "shadow", and "group" databases.