For the most part, the Sons of Liberty conducted their events against the British prior to the start of the war. During the revolutionary war, the Sons of Liberty did not play a part except for those who individually within the organization fought for the Continental Army.
As a whole, the Sons of Liberty did a few things including helping to communicate what the British was doing as well as staging protests. Prior to the war, they conducted and protested the taxing by the British which eventually led to the American Revolutionary War.
They were directly involved with the Boston Tea Party where the Sons of Liberty disguised themselves and walked onto the British ship to dump large amounts of tea into the harbor.