In the meantime, I just noticed that Addison-Wesley has a couple of very good UML books on sale for 35% off. If you're serious about becoming expert with Rational Software Architect (or Software Modeler), I highly recommend you pick up one or both of these books. They are:
- The UML User Guide, 2nd Ed. by Rumbaugh, Booch, and Jacobson. This provides a good introduction to the UML and describes how to use it to model software systems. Good for beginners and intermediate UML users.
- The UML Reference Manual, 2nd Ed. also by Booch, Rumbaugh, and Jacobson. Rigorous reference on the semantics and usage of all UML elements. Recommended for intermediate and advanced users of UML.
Note that both of these books were originally released in the late 1990s. Thse second editions have been fully revised to reflect the many changes present in UML version 2.
The Reference Manual includes a CD with an electronic version of the book, which is really handy if you want to quickly look up the definition of some element.