Check your alumni directories for graduates around the same year as your year in the town you want to visit. Most alumni are happy to talk about their towns and give "inside" tips on local restaurants and events that are hard to find elsewhere.
Ask on any list-servers or e-mail (non-work, of course) lists you frequent. As with alumni, folks are usually proud of their town and have something to share.
Use your resources:
Join AAA; the reasonable annual fee is returned in the free maps and guide books.
Get a local newspaper (hard-copy or e-copy) before you go -- check the entertainment section for ideas of what's going on in town.
Collect travel articles that interest you during the year -- save in a Travel Wishes folder.
Enjoy your interests away from home:
Are you a sports fan? Local high school and college sports are free or inexpensive, and many locations have either major or minor league baseball teams or professional football, basketball, or hockey teams.
Have a favorite national store or chain restaurant? Check their websites for nearby locations.
If you enjoy a particular hobby (book collecting, needle work, bird watching) surf the search sites (Yahoo, and Ask.com are good search sites) for those resources and activities in your destination coastal town.