I agree with Brian. You will need a contract that is specific to your business and location. Finding a lawyer can be time consuming but well worth it in your case. You can also check the link below:
There are nationwide and very reasonable.
Good luck to you!
I know right it is really time consuming. You can check this site PDFfiller where you can find blank rental agreement form. You can fill out the form directly from the site. Here is a link to the blank rental agreement form that i used http://goo.gl/dEZOsK. This site also has some tutorials on how to fill it out and a several rental agreement forms.