Every adult who lives in the rental unit, including both members of a married or unmarried couple, should be named as tenants and sign the lease or rental agreement. This makes each tenant legally responsible for all terms, including for the full amount of the rent and the proper use of the property. This means that you can legally seek the entire rent from any one of the tenants should the others skip out or be unable to pay; and if one tenant violates an important term of the tenancy, you can terminate the tenancy for all tenants on that lease or rental agreement.
LIMITS ON OCCUPANCY
Your agreement should clearly specify that the rental unit is the residence of only the tenants who have signed the lease and their minor children. This guarantees your right to determine who lives in your property -- ideally, people whom you have screened and approved -- and to limit the number of occupants. The value of this clause is that it gives you grounds to evict a tenant who moves in a friend or relative, or sublets the unit, without your permission.
TERM OF THE TENANCY
Every rental document should state whether it is a rental agreement or a fixed-term lease. Rental agreements usually run from month-to-month and self-renew unless terminated by the landlord or tenant. Leases, on the other hand, typically last for certain years. Your choice will depend on how long you want the tenant to stay and how much flexibility you want in your arrangement.