Some tips from Google:
If you have more than 10 locations, submit these locations via a bulk upload and then request verification for the bulk upload.
If you have two locations, but only one is listed, you can create a separate listing for your other location – create one listing per business.
Fake reviews are against Google’s Comment Posting Policy.
Providing an accurate and complete listing can help your local listing rank better.
Get local inbound links
Take care to get inbound links from local TLDs (top level domains), especially links containing your targeted keywords and city in their anchor text.
Where should you look for such links? Consider the following opportunities:
Contact your local business partners
Get registered with your local chamber of commerce
Get registered with some government agencies
Contact your suppliers
Submit your site to local directories, for example: SuperPages, Yellow Pages, Switchboard, Yelp.
Submit your site to local search engines – Yahoo! Local Listings, Bing Local Listings.
Leave your comments in some local blogs
Only some potential resources for local promotion in the USA are listed above. We bet you will find more directories that are relevant to your business and its location and will give you more targeted local traffic (for instance, in Yahoo! Directory, Dmoz, or Google Directory, or by organic search).
Get the most out of customer reviews and Web references
Other people’s experience in social mentions is very important for someone who considers contacting you. Ask your customers to write a review about your business on their preferred shop site, forum or portal.
If someone wrote a negative review, don’t leave it as is. Contact them to find out why they didn’t like your service – maybe you can change their opinion. Respect has always been a winning tactic.