You're going to get the standard answer around here: Applying UML and Patterns by Larman and UML Distilled by Fowler, which are the two books recommended by IBM. That being said, also go to ObjectsByDesign.com as they have plenty of good review material there. And I found OOAD@Whiz useful for review.
Theodore Jonathan Casser
SCJP/SCSNI/SCBCD/SCWCD/SCDJWS/SCMAD/SCEA/MCTS/MCPD... and so many more letters than you can shake a stick at!