New customer information leaflet?

[Skxawng]

Hi, my bro in law is setting up a window cleaning business. I mentioned that I've seen on here threads about making a new customer information leaflet or sheet with all the information they might need and policies like payment terms, weather, complaints etc. Basically getting them to agree to your terms before you start to avoid problems down the road.
I can't find them in here now so can anyone offer any tips for how they've done it or even better, have a template?
Thanks, Laurie