Going to Ocho Rios, Jamaica next week. What do I need to know?

From people who have been there, done that in Jamaica (particularly Ocho Rios), what should I know before I go there? We'll be staying at Couples Resort, Ocho Rios but would like to travel to Kingston, Dunns River, Black market, and some other places. We want to have fun but be safe and not wind up killed. Thanks for any info!