Web sites are composed of a hierarchy of elements that work together as a whole to shape user expectations. Site design is the point at which you assemble your planning work on information architecture, navigation elements, and user interface wireframes and begin to structure an actual site in html and css. But before you begin this process, situate your site appropriately within the context of the web and your organization.
The larger web environment shapes the expectations that users and readers bring to any site. As interface expert Jakob Nielsen points out, your readers spend the overwhelming majority of their time on sites other than yours. Any site design should consider the larger design norms and user expectations of the web and avoid self-indulgent exercises in interface or design novelty. Your site will succeed and draw visitors and customers if you provide great content and services. No site succeeds because it has a cool home page. Your site could easily fail if you ignore user expectations and create a peculiar, unusable framework for your content.
If you work within a larger organization, always make your relationship to the larger enterprise a clear and meaningful part of your site design. If your institution has an identity program or a web template system, use it. Adopting the design standards of the larger enterprise can save you a lot of time and money. Institutions notorious for poor governance—universities, government agencies, large nonprofit agencies—also often have chaotic web sites. Large companies sometimes have the same problems, but the standards and norms of corporate identity programs are well established in the business world, and most corporate sites start with the expectation that everyone will share a common look and feel and user interface and that each discrete corporate site will project a clear relationship to the parent enterprise.