Marketing Help For Internet Based Business

I'm a college student very interested in educating myself further in
Marketing.  I'm on the board of directors for an S-Corp. We're an
internet based business who sells leverage--traffic.  We try to build
'friendly' community based websites to benifit both the business
owners in that specific town as well as the community through features
such as forums, community calendars, etc.

I've spoken with a few individuals regarding marketing strategy; and
decided to persue two main ideas--targeted postal mailings, and
perhaps some form of a 'web conference'.  The majority of our site
traffic comes from visitors outside of the town; primarily tourists
interested in visiting the town. Therefore, we think its in our best
interests to target visitor oriented business (bed and breakfasts,
outfitters) -- anybody that really benifits from tourism.  Do you
think this would be an appropriate strategy?  Does our view need to be
refined more? The towns we are looking to target range in population
from 2,000 to 25,000 generally.

Any suggestions for forms of mailed advertising that have been
successful would be greatly appreciated.  I've heard several people
say that postcards seem to be an effective medium.  Also, since we are
a web based business, we would like our contact medium to be
online--so our only contact method would be only via our website.  Any
thoughts on this? Good bad indifferent?

Also, any suggestions for documenting our marketing attempt? What kind
of things should we be looking for after we send out our mailings? 
How can we get feedback from the customers that do utilize our service
on what was and wasnt effective about our marketing strategy?  Any
other input would be greatly welcomed.  I'm very new to this--So I'm
open to any advice!

Thanks very much!