X.500 Standard status
X.509 Related activities
How to be involved
Tutorial section 1
Tutorial section 2
X.509 at work
Dr. David W. Chadwick has written a comprehensive book covering important X.500 features. This book is now provided online and may be found here. This book was published in 1994 and describes many essential X.500 features and is valuable reading also today.
The Telenor magazine Telektronikk has a short introduction to X.500 written by Erik Andersen. This article may be found here.
A PowerPoint presentation stored as a Web page may be found here.