When we look at the main idea of corporate or business websites, it becomes apparent that their construction is similar to static websites. The only difference is that they are much bigger (they have more pages and more content) and the design seems much more official. Also, most businesses like to publish some announcements occasionally, so a blog-like functionality is required too (but it still won't take the role of the main element on the site).
In essence, creating a quality corporate site with WordPress is all about picking (or building) the right theme. If you do a quick research on the Web, you'll see that most corporate sites (at least the good ones) feature hardly any design. The thing that makes them stand out is their very subtle branding (through a certain color scheme or clever use of logos) and stellar navigation layout. What this means is that the easiest way to build a great corporate site with WordPress is to: