You could see my posts in Server Forum, but in short, here's a good set of HOWTOs
http://www.server-world.info/en/note?os=CentOS_6&p=ldap.
See Right Hand menu, and my notes in my posts as mentioned.
Note that according to my researches, there's a high turnover in SW versions & cfg file contents etc, so the above works for 6.4; you might(?) need to tweak for 6.2.