According to John Aubrey, cribbage was created by the English poet Sir John Suckling in the early 17th century, as a derivation of the game "noddy". While noddy has disappeared, crib has survived, virtually unchanged, as one of the most popular games in the English-speaking world. The objective of the game is to be the first player to score a target number of points, typically 61 or 121. Points are scored for card combinations that add up to fifteen, and for pairs, triples, quadruples, runs, and flushes.
Cribbage holds a special place among American submariners, serving as an "official" pastime. The wardroom of the oldest active submarine in the United States Pacific Fleet carries the personal cribbage board of World War II submarine commander and Medal of Honor recipient Rear Admiral Dick O'Kane on board, and upon the boat's decommissioning the board is transferred to the next oldest boat.
Above information is from Wikipedia which also has full rules and a wee bit of strategy for the game.
There is even an American Cribbage Congress, http://www.cribbage.org/, to help perpetuate this great game.
Next to maybe tennis I think cribbage has some of the strangest set of rules and scoring systems around. This does not diminish the game, in fact it is one of the more intriguing parts of it.