Study rollover. Look at the rules. Know exactly what you are getting into.
I would take a look at Betonline. Before depositing, ask them: "Will you match BetJamaica's 100% bonus on a $100 deposit?" They will say yes. Then deposit $100 to try it.
Or, you can play at BetJamaica also. Both books are excellent.
I haven't played at BetMania, so I cannot comment on them.