Microsoft Patterns & Practices has created an Enterprise Library FAQ with answers to your most frequently asked questions. These answers were probably tabulated from the Enterprise Library Forums on CodePlex. This is a great resource to view before asking a question in the forums.
I just gave two presentation on Enterprise Library and Unity at the South Florida Code Camp 2009 and to the Southwest Florida .NET Developers Group in Ft. Myers and a few of the questions in the FAQ came up during the presentations ;)
I am sure this list of Enterprise Library Questions and Answers will continue to grow over time. Check it out here.
Feel free to check out the tutorials here as well: Enterprise Library Tutorials.
You can also find them on my personal website:
Don't pay any mind to the versions as 95% of the tutorials are applicable to all versions of Enterprise Library.
Hope this helps.