Hi Matt,
I have a test box in a virtual machine with CentOS 5.4 and eDirectory 8.8.5 (8.8 SP5) that I use to test LDAP authentication and enrolment code changes.
I have disabled TLS for password-based LDAP authentication to eDirectory (to make it easier to setup from Moodle's point of view).
I have a tree called MOODLE, with an organization called 'novell-edir' inside it, and an organizational unit called 'users' inside it, for the administrative users.
I have a user called 'ldap-user' inside the 'users' ou, with read rights to all attributes of all users and groups. This is the user I use to bind to eDirectory from Moodle.
Then I have another ou called 'moodle' hanging from the organization object. Inside the 'moodle' ou, I have a 'users' ou where I have two ous called 'students' and 'teachers'. And something similar for the courses (LDAP enrolment).
One little detail: I set the 'uid' attribute of the user objects to hold the username, instead of using the cn (which some people do).
The following image shows the LDAP authentication settings I use:
http://img683.imageshack.us/img683/2186/moodle19administrationu.png
Hope that helps.
Saludos. Iñaki.