When I was in the university, I used to use the book named "UML and the Unified Process: Practical Object-Oriented Analysis and Design" of Jim Arlow. And until now, I'm still using that book, if I got some doubt on UML concept to be applied to my Java codes...
I have read other books like
"The Unified Modeling Language User Guide" of Grady Booch and "Applying UML and
Patterns: An Introduction to Object-Oriented Analysis and Design and the Unified Process (2nd Edition)" of Craig Larman
But I like Jim Arlow's book the most and it will be my reference in the future as well...
All above are just my opinions...

Co-author of SCMAD Exam Guide, Author of JMADPlus
SCJP1.2, CCNA, SCWCD1.4, SCBCD1.3, SCMAD1.0, SCJA1.0, SCJP6.0