A more lightweight book is "UML for Java Programmers", which will teach you the 20% of UML that will suffice 80% of the time - and how to use it effectively. In my opinion one of the best books to start with.
The soul is dyed the color of its thoughts. Think only on those things that are in line with your principles and can bear the light of day. The content of your character is your choice. Day by day, what you do is who you become. Your integrity is your destiny - it is the light that guides your way. - Heraclitus