Nice and plain practical guide to UML.
“UML for Mere Mortals”, 2004.
Authors: Robert A. Maksimchuk, Eric J. Naiburg
Publisher: Addison-Wesley Professional
The book title suggests the books aim, to provide a practical introduction to UML with emphasis on the 20% of the UML standard that will be used 80% of the time on real project work.
I think the book succeeds in this aim. The explanations of the use of the notation is clear and useful. For many if not most IT professionals, UML will play a role just occasionally. When it is useful, it can make a big difference in terms of aiding a common understanding in a project team. So, it pays to be just familiar enough with this modeling tool, and this is a book that helps.