Once the property owner has selected a tenant, the parties will need to enter into a lease or rental agreement.  The lease is a formal contract that sets out the terms and conditions of the tenancy and the rights and responsibilities of the landlord and tenant.

The lease is a contract that governs the landlord-tenant relationship.  It transfers possession, use and enjoyment of the property from the landlord to the tenant for a specific period of time and for a stated monetary amount (rent).  The agreement also lists the various rights and responsibilities of the tenant and the landlord, such as a payment of rent, payment of utilities, use and up keep of the premises, subletting, security deposits, and other issues relating to the rental unit.

The agreement should be in writing.  Most jurisdictions have a adopted a legal doctrine called the Statue of Frauds; this doctrine states that contracts that cannot be performed within one year must be in writing in order to be enforceable.  To comply with the Stature of Frauds, leases of one year or more must be in writing.
(As a practical matter, all leases, no matter what the duration, should be in writing, since the written document provides a record of the terms of the landlord-tenant relationship.)

The agreement should be signed and dated. Both the landlord (or rental agent) and the tenant should sign and date the agreement.

A copy of the agreement should be given to the tenant.  The tenant should be provided with a copy of the signed lease for future reference.