Boomers
Operates a number of amusement and water parks throughout the United States. Offers news, employment opportunities section, and information on the Fun Club.
http://www.boomersparks.com

Theme Park Adventure Magazine
Includes current and back issues, ordering information, and park news.
http://www.themeparkadventure.com/

Anheuser-Busch Adventure Parks
Operator of parks such as Sea World, Busch Gardens, and Adventure Island. Provides links to owned facilities and online ticket ordering.
http://www.4adventure.com/

Ripley's Believe It or Not!
Offers museums and attractions in multiple countries focusing on odd and amazing things. Provides videos, details about exhibits, and their history.
http://www.ripleys.com/

Universal Studios Themeparks
Guide to Universal's Orlando, Hollywood, Japan and Spain themeparks, including information about tickets and vacation packages.
http://themeparks.universalstudios.com/

Cool Works
Seasonal career positions in amusement and theme parks.
http://www.coolworks.com/amusement-park-jobs/