Try Nolo Press (nolo.com) — famous self-help legal publisher that sells books and forms written by lawyers for laymen.

As a general reference I’d recommend the book “Landlording” by Leigh Robinson.

(Yeah, I’m a lifelong renter who still hasn’t closed on his first home. But my parents were reluctant landlords for years, and as the kid with the best grades in English I helped type up all the legal paperwork.)