INNspiring.com | Innkeeper Forum
A very active innkeeper forum, where you can get a lot of your questions answered. They also have good links to innkeeper resources.

The B&B and Country Inn Marketplace
Inns and Bed and Breakfasts for sale. A marketplace to find your new inn property, or to list your B&B for sale.

Cruising-America
One of the original bed and breakfast directories is being relaunched, and they are allowing innkeepers to add their B&B listings for free.

About.com: Bed and Breakfasts
Lots of good information about bed and breakfasts, with specific sections for aspiring innkeepers.

The Inn Broker
Bed and Breakfast sales and consulting. An absolute must if you are considering a property in Michigan

B&B Team - Inn consultants and brokers
Sale listings, articles, seminars, and all-around great insight into the industry. One of the first B&B sites I ever visited.