If you are interested in finding out more about Racketlon the best place to start is at http://www.englishracketlon.org/ – this has details of the sport, a brief summary of the rules and information on when and where tournaments will be held.  Wikipedia also has a short section on Racketlon

The site also has an excellent “Links” section which provides a whole host of online resources about Racketlon.

There is also a very active Facebook Group which is kept up to date and carries details and links to all upcoming (and past) events.