Next you need to register your business name. The fastest way is known as the DBA which is an acronym for Operating As. Example: you name DBA Steamtown Cleaning Company. In most areas you can register your DBA at the county clerks office, you could also work with an online company like Legalzoom to an individual to. As business grows might want to generate a corporation or LLC to remove yourself personally from organization. Then the business is subject to any potential lawsuit properly personal assets are paid for. I'm not an attorney at law and would prefer not to give legal advice, this is the basic overview but a legal counsel can really give you the complete explanation.
Make the actual contract at length so who's covers every small involving the office cleaning matter. Ensure that realize everything