One of the best places to start is by looking for past and current customer reviews. If a company has nothing but terrible reviews from actual customers, there probably isn't a reason to continue gauging their credentials. Customer reviews are powerful, and can best identify a company's business ethics and workmanship. But keep in mind that sometimes, customer reviews are very one-sided. If there are only a few poor reviews, do not let this thwart you from learning more about the company, or using their services.