Square dance consists of a variety of individual 'calls' which are sequences of movements. Learning the movements of each call and practicing them is the way we learn to square dance. Here are a couple of supplementary aids that can help with learning the movements.
The Tam Twirlers club has posted animations of each call. They can help with visualizing the exact sequence of movements. http://tamtwirlers.org/tamination/info/index.html (In the green navigation bar, click on one of the levels, such as Mainstream, then click on one of the calls and play the animation.)
The Saddlebrook Squares club has posted video lessons that demonstrate each square dance call with real dancers. http://www.saddlebrookesquares.com/lessons.htm
Useful Organization Sites
There are many other square dance organzations that provide online resources. Here are several of the major ones.
The North Carolina Folk Round & Square Dance Federation web site, http://ncfederation.org/, has useful lists of clubs and callers in North Carolina plus other info about dances it sponsors, including the NC state convention dance weekend in August.
The United Square Dancers of America web site, http://www.usda.org/, has info about its national programs, plus databases of clubs and callers all over the country, and other useful links and info.
The CALLERLAB (International Association of Square Dance Callers) web site, http://callerlab.org/, in addition to its database of callers, contains the "standardized" dance programs with detailed (really detailed) definitions of square dance calls directed toward callers. But they can be helpful to dancers in understanding details of calls.
The Association of Round, Traditional and Square Dance is an umbrella organization for promoting and raising awareness of those dance forms. It's site, http://arts-dance.org/, contains some helpful info. ARTS also sponsors the you2candance.com web site that is very useful to help potential dancers learn what square dancing is all about.
Other Useful Web Sites
The commercial Western Square Dancing - DOSADO.COM web site, http://www.dosado.com/, has many useful resources for square dancers, including extensive lists of clubs and callers. Also, some square dancers may enjoy the square dance humor articles by Nasser Shukayr - some may not.
The Where's The Dance web site, http://wheresthedance.com/, currently seems to have the most up to date and extensive lists of square dance clubs and dances all over the world.
The Dance Gumbo web site, http://www.dancegumbo.com/, is a good resource for info about all kinds of social dancing in the Triangle area.