1.- Post dated cheques are no longer an issue since there is a new legislation stating that it can be exchanged anytime before the post dated on it.

2.- Register the contract with proper authorities to avoid future issues with landlord since it is the inly legal document to back you up in case of any unwanted problem.

Any additional information i would suggest you to go through the provided link

http://www.qatarliving.com/node/74099#comment-285114

Regards!!