Enterprise Directory and Security Implementation Guide: Designing and Implementing Directories in Your Organization (The Korper and Ellis E-Commerce Books Series): Charles Carrington, Tim Speed, Juanita Ellis, Steffano Korper: 9780121604523: Amazon.com: Books. So this was written in 2002 and for its time it was good and helpful. However since technology moves on, this is nothing more than a historical reference now. Avoid.
What is interesting is that LDAP historically has been little used compared to Active Directory. The perception that AD was easier to use always gave Microsoft an advantage. I used LDAP at a few companies I worked at and I found it easy to use. I like the Open Authentication of the Mac OS Server as well. I thought that was even easier than Active Directory. I hope that we can retire AD soon. The days of having local windows servers seems like it should have been over a decade ago.
The main problem with having local IT services and hardware is that there is a tremendous cost to companies to maintain all of that infrastructure. With the low costs of cloud computing it doesn’t make sense anymore. Take for example Amazons unlimited data backup storage for $60 they recently announced. No IT company can compete with that. So it would be foolish not to use it. I am not going to use it because I don’t trust Amazon with my data, but other people might be much better served by that. With all the free plans and offerings by companies, you can almost exist without paying anything to anyone anymore for any computer services. It is really incredible how competitive computer services are.