Clubs get together and ride regularly in groups with varying numbers of riders.
Race teams here train and compete on the mostly amateur level. They not only work on your speed but your bike handling skills and how to ride in close quarters with other racers. They also teach you tactics.
Club ride schedule:
http://www.fremontfreewheelers.org/M...09Calendar.pdf
Race team site:
http://www.fremontfreewheelers.org/RaceTeam/
Feel free to contact the race team with any questions you might have. They might have some training rides you can go on to check them out.