Documentation for Crowd 2.3. Documentation for other versions of Crowd is available too.
This is a basic tutorial on using a wonderful Eclipse-based LDAP browser, known as Apache Directory Studio, to gather the information you need for your LDAP configuration.
If you are an LDAP newbie, there are two great articles that may help you gain a better understanding of LDAP and LDAP search filters before you begin using Apache Directory Studio: