Hi,
first post from me to the list and no I'm not an LDAP expert and I still have a lot to learn about OpenLDAP. It is possible to learn it with the existing documentation but it takes some time!
I don't understand how complicated software like this gets widely deployed and accepted when documentation on it is so limited and unclear... It is quite difficult to get ldap to function properly and am left with the question of how the hell anyone can figure out how to get this piece of software to do anything! If there was some form of acceptable documentation....
I have read a lot about LDAP and OpenLDAP in 2 Books and various articles in Unix/Linux magazines.
Take a look at your local bookstore or Amazon, etc.
LINUX MAGAZINE has puplished an article about LDAP Authentication:
Part one: http://www.linux-mag.com/id/3722/
Part two: http://www.linux-mag.com/id/4124/
I think they are good for a start.
And there are a lot of other books and sources on the Internet, too. Have a look at
http://www.openldap.org/doc/admin23/
http://www.padl.com/Contents/Documentation.html
Michael