Freemasonry is a worldwide philosophical, charitable, and social organization that makes good men better.
Here's a short essay I wrote about what Freemasonry is and isn't.
Gary Dryfoos maintains a very extensive Masonic site.
The Grand Lodge of Massachusetts was the first Grand Lodge with a web site.
The Philalethes Society is an international organization of Freemasons interested in researching the history and philosophy of the Fraternity.