When I was 14, I joined the Eastern Loggers, a group that developed a layout based on a series of books on railroad logging in Pennsylvania. That layout has now gone to a museum and will soon be on display. To read more about that, checkout my post on the HAVOC website.
The club and my participation was not just about model railroading, but it also formed me as a person, a modeler, a designer/engineer, a manager, etc. Click the link to my post about the layout and my experiences to learn more about the layout.