Graphic designers focus strictly on the visual artwork for a project. Some specialize in certain areas like logo design. Graphic artists usually work with print and web. They can design brochures, business cards, annual reports, advertising material and give you a high quality professional look. Many companies hire a designer for the graphic design then hand that over to a web designer or developer to incorporate into a website.
Graphic designers usually charge based on experience, designers with less experience may save you money but more experience designers will almost always deliver a higher quality product. Before you choose a graphic designer you should review other design projects they have worked on, and contact past clients if possible. Some designers charge per project or per hour. Make sure you have defined the requirements for your web project and both of you have an understanding in writing of what is expected. See USDOL Definition of Graphic Designer .