Services (landscaping, home repairs etc)
Any New business
Restaurants
Motels
Bed and Breakfast
Arts and Crafts
Single-Line stores (Pizza, books, shoes etc)
Real Estate
Hair Salons
Clothing shops
Antique shops
Travel Agents
Builders
Professional (health, accountants, lawyers etc )
Home-based (mail order, niche marketing etc )

Information that could be included:

Contact Details
Location (map )
Company Information
Product or Service
Samples of your Work
Sales and Specials
Contests, Promotions
Menus
Reservation form
FAQ's
Newsletters
Staff Profiles
Special Customers
On line Coupons
Coming Attractions
Guest Book
Links to Interesting Sites

Benefits to your business:

Showcases your work
Generates interest
Generates orders
Attracts new customers
Reduces phone time
Compete with large companies
Low advertising costs
Serves local market
International presence
Enhances your business image
Niche or Specialised market exposure
Gather data/feedback