Getting your site to pop up in the map results in Google Search is a very important place to be. Of course it's almost impossible to be there for every single keyword or key phrase you want, but you can greatly improve your Google map performance by narrowing down to the keywords or phrases that are the most important to your business. Now one of your best chances of getting higher in Google is to create and cultivate a Google Plus page, and you will be automatically added to Google Maps. Because Google is a narcissist, it loves its self and all of it's own content!
Here are some tips on how to increase your website ranking overall as well as increasing your Google Maps ranking.
Verify your listing and make sure that your business information is correct. Your map will not show in Google search results until you verify the address. You can verify your business address by having Google send you a postcard with a validation code. Ensure that you fill out all the sections on your business page with as much information as possible. Include keywords in your listing description. Also, duplicate pages is a horribly bad thing! If there happens to be another business page or an old Google Maps page you need to get rid of it - these duplications is a huge penalty.
Customize your Google+ page URL. Having a numbered page is harder for people to find and type in if they are given a written invitation to contribute to the page. It's more then likely having your name in the URL will help as well.
Add User Reviews. Good user reviews (stars) shows right in the Google maps results, and it can be highly influential to potential customers. Google likes to see that your customers are engaging with you, and this will be another ranking factor for your page to get your name in there. Be warned though, you have no control over what people write, and a bad review can be read by everyone. Be sure to give out the link to your Google page to your favourite customers. The more good reviews you have, the less likely a bad review will bring down your rating. Remember that how you respond to a bad review is extremely important. A diplomatic and elegant response to a bad review can be the difference between winning a new customer and turning a customer off.
Increase the traffic to your Google+ page. You can get more traffic to your Google+ page by #1 - Posting good quality content on your news feed, #2 - Post links to your Google+ page on your website and other sites to get good quality visitors to your page.
Some items that negatively affect your Google+ ranking are:
Using a 1-800 number for your phone number. Google wants to see a local area code that matches your business location address.
Having multiple addresses or multiple listings for the same business. If you have duplicate addresses you should solve it as soon as possible! Listings with the same address and phone number can also have an affect on your ranking.
Negative customer reviews. While you can't get rid of them, you can respond elegantly to assure customers that you are not ignoring potential issues, and you can ensure that you have enough good reviews that the bad reviews don't affect your ranking.