Before you get started, it is wise to log onto GetListed.org.   Here you can put your business name and zip code and click the "Check my listings" button to see if a listing for your company exists.  If a listing does exist, then you may go in and claim it.  If there is no listing for your company, you will need to create a listing by going to your Google Maps Listing at the Listing Business Center.  Sign in using a gmail email and click on the "List your business" tab.

To create an optimized Google Maps listing follow the instructions below.  Simply filling out your local listing without giving it real thought is a big mistake.  The Google Maps Listing should be given the same time and devotion you give to your on-page SEO for your website. Much of the information below comes directly from Google Places Quality Guidelines.
 

Google Maps On-Page Optimization

Put some thought into the following elements before you summit your Google Maps listing.  Remember, so  long as you have access to your listing, you can go in an edit it.  It isn't as if it cannot be changed.

Business Name:

• Do not include marketing taglines in your business name.
• Do not include phone numbers or URLs in the business name field, unless they are part of your business name.
• Do not add keywords in the business name unless they are part of the business name.

Address:

• Make sure you enter a precise address where your business physically exists, not broad city names or cross-streets. P.O. Boxes are not considered physical locations. Listings submitted with P.O. Box addresses will be removed. 
• Do not create more than one listing for each business location, either in a single account or multiple accounts. 
• Businesses that operate in a service area, as opposed to a single location, should not create a listing for every city they service, they should create one listing for the central office or location and designate service areas. (Learn how to add service areas to your listing.)
• Do not create multiple listings to cover more than one specialty even if your business has multiple specializations, such as law firms and doctors. You may create one listing per practitioner, and one listing for the office.
• Do not include information in address lines that does not pertain your business’s physical location (e.g. URLs, keywords).

 Category:

• Choose at least one category from the suggestions provided.
• Categories should say what your business is (e.g. Hospital), not on what it does (e.g. Vaccinations) or things it sells (e.g. Sony products or printer paper). This information can be added in your description or as custom attributes.
• Categories should not contain locations (for example, Dog Walker Los Angeles).
• Only one category is permitted per entry field. Do not “stuff” entry fields with multiple categories.
• You should do some searching with category keywords in Google and note which keyword categories trigger a 7-Pack.  Those keywords that trigger the 7-Pack are those you should consider using.  Do some good keyword research to ensure that the keywords you are choosing have a decent search volume. 

Content/Media:

• Add photos & video, etc.  People are very visual and expect to see images and videos when online. 

Coupons:

• Coupons could be what sets your business apart from other competitors found in the local listings.  Coupons are also a great way to track sales generated from your local listing on Google.  NOTE: If you have coupons running on other local listing sites, make sure you create different coupons so that you can track where your customers are finding you.

Verification:

• Once your listing is complete, it will need to be verified.  You will be required to input a PIN number which Google will provide.  You can obtain this verification PIN in 3 ways.
  • Phone
  • SMS – Text Message
  • Mail – They send a postcard with a PIN # via USPS
  • If you verify using your phone or cell phone text, then your listing will go ‘live’ with all the changes immediately. To verify your listing by phone, you must be available to answer your business phone immediately upon clicking the "verify" button.
  • Not all verification options may be available due to several reasons:
    • The mailing address or the phone number do not match the listing, meaning Google's records indicate different information than what you are providing.
    • Too many businesses have been verified with the same phone number or the same address.