Demystifying LDAP (O'Reilly)
If you've been struggling to understand what LDAP is and how it can be useful to you without picking up a 1,000-page tome, look no further. LDAP is great for some problems, pretty good for some others, and completely inappropriate for yet another batch of problems. In this first part of a series on understanding just what LDAP is, I hope I can help make LDAP easier to deal with by explaining, in English, what LDAP is and what it is good at. After that, looking at the data and writing code will be much easier."