This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
FYI, we discuss these choices in the Timer section of EJB 3 in Action. To make a rough statement, Quartz or the application server's scheduling support is probably right for about 80% of real world cases. This will change in EJB 3.1 because it adds cron-like scheduling support which is a lot simpler than either of these existing options and is standards based/vendor neutral.
Independent Consultant — Author, EJB 3 in Action — Expert Group Member, Java EE 6 and EJB 3.1