Local SEO is the type of preparation your website needs if most of your business is done locally. If you're doing business on a regional, national, or international basis that's an entirely different ball-game (see Link-Building).
Search engines depend upon website owners and their opinions of other websites to determine which pages to show someone in a search-engine results page (SERP). Makes sense. If a webmaster likes the content on another site he's more likely to link to it as a resource. Each link is a vote of confidence. The more links your site gets the better you show up in search.
For local businesses, however, "citations" are viewed as links. A citation is an instance where your business' name, address, and phone number is published/displayed. The more times that happens, Google reasons that your site, your business, is that much more relevant and popular.
There's a bit more to it than that but that's the gist of it. If you do business locally you need a consistent citation-development program. This program comes with all of our website packages (except the DIY package), it's that important.