Need advice with new tenant

[Barrington M.]

I have an basement that is completely set up to be rented out, full kitchen, bath, bedroom, office and private entrance. My concern is that is not a legal apartment because I have not yet claimed it on any tax income. I am aware that other long islanders do this because of the high taxes and cost of living in New York. What should I do in terms of creating a lease for a new tenant being that it is basically unenforceable if I had to evict a tenant. If I did not create a lease what is the best way to establish ground rules for the tenant so that preventable issues/questions are taken care of upfront? Any advice for this type of situation from people who have gone through this or know someone who may have gone through this?