Google dominates the search field (both Web and local) the first place to list your local business should be Google and their Local Business Center. Not only will Local Search Optimization help consumers find your physical location, but also enhance search results for your business and help keep up with the competition.
Once your presence is established and accurate, move on to build your local listing in other search engines, like Yahoo! and Bing. Google is the largest search engine, with an estimated 75-85% market share.
Most of your online efforts should be focused on making sure your business has a prominent presence in this search engine. While this can be accomplished by creating a website for your company and using search engine optimization techniques, it could take several weeks or even months before your site ranks well and starts to see significant amounts of traffic. The best way to make sure your company has a strong presence is through the use of Google Places.