This is a little primer I put together for configuring Mac OSX to authenticate to eDirectory through LDAP. There is some information out there,
but I found nothing that bundles all of the "oh, watch out for that's" together. I hope you find this useful

Step 1: configuring the OS X client to make an ldap connection, and map correctly to eDirectory
Configuring the Mac OS X client

Step 2: Testing your ldap connection, and making sure ldap attributes map correctly between OS X and eDirectory
Testing the client to ensure ldap connection works properly

Step 3: Extending eDirectory's schema using ConsoleOne
Next, you need to extend eDirectory's schema with a file called applev2.ldf from macenterprise.org. when you obtain this file, you use ConsoleOne->Wizards tab->NDS Import->Import LDIF
There's also a pdf that accompanies this file that describes some of the steps above.

Step 4: Dealing with existing eDirectory users
Any users already in the tree, are going to need some things applied to their user object. Now that the schema is extended, eDirectory knows there's something called apple-user and apple-user-homeDirectory, among other things. To make authentication work, some objectClasses need to be added to each user in your tree using ConsoleOne:
posixAccount objectClass, which need these attributes: uidNumber, gidNumber, loginShell, homeDirectory
apple-user objectClass, which has an optional apple-user-homeDirectory attribute that should be added.

I've written some java classes that can be used to modify all users at once as opposed to individually editing every user in consoleOne :-(

If you have any questions, feel free to email me at cperry@hmdc.harvard.edu
p.s. There's also a good webcast from macenterprise.org on the subject