you may want to check on below:

1. Is it a direct contract with the firm or via the agent? This will affect you payroll
2. All the leaves you are entitled to. note that you can take non-pay leave
3. Do you follow same working schedule as other perm staff? Do you need to support on holiday?
4. Do you have medical claim? What is the scheme?
5. What is the notice period reqiured to either side for termination of service. Is there any penalty?

Think you can google as well