People working with Active Directory will now that there are loads of tools and scripts to get information out of AD. Besides that, there are often situations at companies that require to setup one or more forests and what is the best approach to do this? Robby Allen has wrote a book called "Active Directory Cookbook" where those practical examples are discussed. Dutch people can order it at Computer Collectief (click here) and I can really recommended it. On the O'Reilly site there is a sample chapter in PDF format.