Google reports looking at over 200 characteristics of your web site to determine where your site should rank. One of the most important characteristics is the number of inbound links, i.e. the number of other sites linking to yours.

There are LOTS of ways to build links to your web site and generally, the more you have, the better. The key is, to have links to your site from quality sites, not just any site. Numerous costly services are available, but there is much you can do on your own.

First:  Start with the basics.  All businesses have business relationships. Make sure you have links from suppliers, distributors, chamber(s) of commerce, trade or professional organizations, and any firms you partner with.

Second:  Expand your reach.  Set a small budget, perhaps $200 annually, and join private sites. Some will be free or offer free 'basic' listings, but charge to make a link active. Others may simply charge a small fee and/or offer 'enhanced' listings at greater cost. Occasional sites will require membership.

Some NH sites to consider:

DirectoryNH.com
NewHampshire.com
NH.com
NHMade.com
NHOutdoors.com
UpStateNH.com

Some national sites to consider:

DMOZ.com
Manta.com
Yellow Pages Classifieds

Third:  Leverage social media.  There are scores of social networking sites, most of them good, and nearly all of them allow you to list your site or favorite sites. Take a long afternoon, write a business profile, and submit it everywhere you can find. Consult Wikipedia's Social Media site list and SitePoint's list for business networking sites.

Fourth:  Put pictures to work.  If your business has unique products, or is picturesque in any way, get photos out there. Give the photos file names that are chock full of keywords (i.e. whitemountainshotel.gif or lebanonrestaurant.jpg), and submit them all around the world wide web. Good places to start include Flickr and Photobucket. If you want to get really serious, consult Wikipedia's list of photo sharing web sites. Make sure you have the rights to any photos you are distributing.

Fifth:  Get involved.  Locate forums dealing with your business topics, and ask or answer questions. Most will allow the posting of your profile and/or contact information. Many forums are moderated and most have rules, so be sure to be courteous and work within the rules. Simply search "<your business topic> forums" at Google to find the best ones for your business.

CAUTION: Save yourself some headaches. If you spend any appreciable time link building you will get a LOT of welcome / confirmation / please update sorts of emails, and keeping track of them can be maddening.

1) Create a new free gmail or other account for confirmations, and 'forum chatter', etc.

2) Create a new username / password combination especially for use with these sites and use it consistently wherever possible.

3) Keep a detailed list of everywhere you have submitted profiles, photos, requested links, etc. Be sure your list includes user name & password combinations.

Should you ever change business locations or phone numbers, or if your business ever merges, changes names or web addresses, or if you decide to delegate these maintenance tasks, life will have fewer headaches and be easier later if you have good records. I can't even recall the number of clients I have helped clean up outdated business information around the web.

Lastly:  If you plan to seriously undertake link building, consult Matt Banner's Ultimate Link Building Guide, SEOBook's article, Build Link Popularity, or the Link Building Strategies at Search Engine Watch.

Tip: Sounds like a good project for a summer intern to me!