The easiest way to do it is to use Directory Access in Utilities. You'll need to configure the LDAP plugin to point to your server. Then you can add it to the search path under the Contacts tab. Address Book, Mail, and any other app that supports Directory Services will then automatically be able to use your LDAP server for contacts.
As for setting up the server, read the Admin Guide on the OS X Server CDs. I think it's on the Admin Tools CD.