This again is not an easy question and is directly tied to SEO. Everyone has a friend or family member that build websites... Well that does not mean they know squat about Site Structure and SEO.
It is hard to find a developer, designer, and SEO or marketing specialist wrapped in one. Smaller companies tend to find one person who can do all these things. The key is to use an open-minded person who realizes that he is in a constant state of learning flux and need so always be gathering data to improve the website.
There are three or more distinct types of persons you need when building a site.
- Devlopers - they build the wireframe or layout the site graphically for you to understand. You need to be integrally involved in these steps or the developer with come up with their ideas for the site, not yours and this can be costly. A good developer well ask for a sitemap first.
- Programmer - This person writes the html and other code for your site from scratch. Some will use Dreamweaver so some other html tools, which does not make them a programmer.
- SEO Marketer - The person will work with the Developer and Programmer to make clean structured code. This is the hard part as separately, most of these geniuses do not play fluidly in the sandbox very well so you have to involved in making sure they are all talking together each step of the way.
Many companies and organizations overlook their Hosting company as a vital part of their vital part of their team. YourHost (an no pun intended), can help make your design life easier. They can help you with setting redevelopment sites and assist in migrating your site and database upon completion. Make sure you can get hold of actual persons in the US that understand what you are doing.