All legally binding documents are written in English. When you sign your contract bring your passport and a photocopy for your estate agent. The estate agent should explain the contract thoroughly to you to avoid any confusion. It is normal for the estate agent to act as a witness to the agreement. If the contract is breached by either party, the other party has the right to terminate the contract.
Rent is paid one month in advance and a one month deposit is required at the beginning of the lease. The deposit will be returned providing the property is in a satisfactory condition when you leave. If you have any outstanding bills, the landlord will use your deposit to pay them.
To terminate your contract, you can freely negotiate with your landlord. Rental agreements will have a defined notice period included in the contract. This period applies if either party (you or the landlord) wish to terminate the agreement.