NEW YORK (TheStreet) -- Most people take friends' referrals, call a company in an advertisement or hire someone they meet at an event. But that shouldn't be the full extent of a service-provider search.Selecting the wrong professionals can cost money and credibility. Management needs to be selective and thorough in its choices. Most companies need four types of professionals: an accountant, a banker, an insurance broker and a lawyer. The following are 10 questions you should ask service providers.