And unless you are a lawyer,
do not write your own lease. You can really shoot yourself in the foot if you slightly misuse a technical term or some such.
Generally speaking, leases are pretty standard documents, and there are lots of standard leases out there. You used to be able to go to the local stationery store and buy one, but you'd be lucky to find a local stationery store anymore.
Nolo Press (
http://www.nolo.com) has a great section on being a landlord, and their book "Every Landlord's Legal Guide" includes a CD-ROM with lots of great standard forms for you to use, including a couple of types of leases -- in both English and Spanish.