Many wikites would rather eat dirt than read about the UML. I'm happy with that (although I'd choose a different restaurant.) For those that are interested here are the UML books I recommend and what I recommend them for.
General UML Books
The books that are considered the most official are those from the three amigos. GradyBooch is the primary author of the user guide ISBN 0201571684 .It's quite a thick book, organized along the ways people might use the UML. That makes it a good book for dipping, when you want to answer such questions as "Modeling Prototypical Instances". JimRumbaugh is the primary author of the reference manual ISBN 020130998X . As you might imagine the reference manual is for those with deep UML questions. When I've needed to delve into those depths I've found it very helpful. IvarJacobson's book is the process guide, which is not strictly a UML book, more a RationalUnifiedProcess book.
I'm too biased to say much about UmlDistilled ISBN 020165783X , so I'll just say it's a very concise (less than half an inch) overview of the UML.
If you are new to objects, a good book that introduces the basics of objects through the UML is CraigLarman's Applying the UML and Patterns ISBN 0137488807 .
Books on the UML from a particular point of view
For the UML from a conceptual point of view, try JamesOdell's Object Oriented Methods: a Foundation ISBN 0139055975 . You won't find anything here about software design, rather it's a book on conceptual modeling - modeling the way people think about the world.
Bruce Douglass's Real Time UML ISBN 0201325799 is a good book on the UML for real time people.
Books on aspects of the UML
A lot of people have trouble with UseCase s. Schneider and Winters's Applying Use Cases ISBN 0201309815 is a good book on the mainstream use of use cases. If you want information on this you should also see what AlistairCockburn has to say on the subject.
You have to be a pretty hardcore UMLer to use OCL (the Object Constraint Language). If you do, however, Warmer and Kleppe's The Object Constraint Language ISBN 0201379406 is a short and clear guide.
The last two recent books show a trend towards short books, very different from what I remember when writing UmlDistilled. If nothing else I hope my book has started this good trend.
I'm not biased, so I can say that UmlDistilled ISBN 0201325632 , is still the best UML book by far. It gives a good sense of the spirit of the UML without getting too involved in the LanguageLawyer level of detail. This is important to me since diagrams are for communication, not about seeing how many different annotations you can put on a single line. The fact that UmlDistilled is one of the shortest methodology books is pure bonus.
I like UmlDistilled a lot also. MartinFowler's writing style is very conversational, very nice.
I had a dream the other night about another book. It was not a UML book, but it was a book that followed the development of a project.. the inside story of how decisions were made. Each time that UML appears in the book it is in a sketch on a cocktail napkin. We hear the dialog between people as they talk about the system. Sometimes they use CRC cards and other times they just sketch UML out on a diagram. On the next to last page of the book, you see disks that hold the masters of the developed software. The last page has a picture of some wadded up napkins.
When reading about Booch's User Guide and Jacobson's Unified Process on amazon.com, watch out! The customer reviews are all mixed up; their database thinks one book is the hardcover edition of the other. (I already mailed amazon.com about that).
IMHO, the absolute best way to avoid this kind of confusion is getting UML Distilled instead :-) --FalkBruegmann
SoftwareDevelopmentMagazine review of the ThreeAmigos UML books: http://www.sdmagazine.com/uml/articles/s996dc1.shtml (June 1999)
Another book I thought was helpful was UML in a Nutshell ISBN 1565924487 --DaveMitchell
I found Catalysis - Objects, Components, and Frameworks a very good, although long, guide to using UML to abstract the important parts of a design. See http://www.trireme.com/whitepapers/books.html --SeanMcclellan?