Much of it depends on how you plan to structure the company. If you are just doing a DBA, then you can file the paperwork with the town clerke at Marlborough City Hall. If you are doing an LLC or other form of structure then you must file an Article of Incorporation with the Secratary of State's office, for that you will need to have an attorney file the paper work for you. If you will be solo for a while, then a DBA with the the city is your easiest and cheapest option. Once you get larger and have employees, you can switch from a DBA to a formal organization for protection and tax purposes.
You will need to establish your company (whether DBA, LLC, Corp etc...) in order to open a business checkig account in order to accept checks made out in your company name. You will also nee this to register your vehicle as commercial, to get commercial auto coverage, and general liability insurance. Some vendors will also only give you commercial/wholesale discounts if you are a liceansed company.
As far as qualifications or specific liceanses go, that all depends on the services you offer.
What kind of services to you plan to offe?
Why do people not respect us as they do other tradesmen? Because every Tom, Dick, and Harry doesn't think he can be a plumber or electrician!