Site Collections in MOSS Explained

I have been asked by Intranet Journal to write a series of articles on SharePoint 2007.  Yesterday they started by posting my tutorial on enabling the creation of site collections from the Sites Directory with a brief description of how things have changed over SharePoint Portal Server 2003.  This is an area which I see causes much confusion for those first approaching working with MOSS which was my original inspiration for writing the article.

You can check out the article here.