In addition to the following websites, don't forget to check out my Diners section and Food section.
Other Places: (that I don't have pages for yet)
Taylor’s Maid-Rite Sandwich (West Des Moines, IA)
Powers Hamburgers (Fort Wayne, IN)
White Castle (Wichita, KS) [gone]
Waddle's (Portland, OR) [gone]
Edgar's Ol' Fashioned Soda Fountain (Elk Point, SD)
Nothing for AK, CO, ID, MS, ND, or WY yet. Any suggestions?
Websites:
Road Food
HollyEats
eGullet Society
Chef Moz
Diner and Restaurant Postcards
Root Beer Stands
Root Beer World
Soda Fountain History: 1, 2
Restaurant China & Memorabilia
Eateries Architecture
Coffee Shops and Eats
Coffee Shops
Sit Down Restaurants in Los Angeles
Fast Food Stands in Los Angeles
Jilly's Drive-ins
Dutch Pantry Restaurants
Horne's Restaurants
Books:
The American Drive-in, Michael Karl Witzel, 1994
California Crazy, Jim Heimann & Rip Georges, 1980
California Crazy & Beyond, Jim Heimann, 2001
Car Hops and Curb Service, Jim Heimann, 1996
Drive-in Deluxe, Michael Karl Witzel, 1997
Fast Food: Roadside Restaurants in the Automobile Age, Jakle & Sculle, 1999
Gas, Food, and Lodging, John Baeder, 1982
Mid-Atlantic Roadside Delights, Will Anderson, 1991
New England Roadside Delights, Will Anderson, 1989
Orange Roofs, Golden Arches, Philip Langdon, 1986
Roadfood, Jane & Michael Stern, 1992, 2002
Selling 'em by the Sack, David Gerard Hogan, 1997
Where Have You Gone, Starlight Café?, Will Anderson, 1998
White Towers, Paul Hirshorn and Steven Izenour, 1979