A phone number is one of the most important pieces of information to prominently display on your website. How many times have you visited a website with the only intention of getting a phone number and calling the business? Have you every visited a website and it takes you 5 minutes to located a phone number threw a maze of pages or perhaps you could not locate a phone number at all.

Ask for references and examples of their work.
Always check a company's references a good web design company will be happy to refer you to their clients. Check out previous projects and don't just look, click on the links and browse around. Is it functional? Is it user friendly?