To get started, head into the Book Room via the Coffee Shop, and make sure you've got a friend with you. This is crucial, because Mancala is a two-player game only.
Club Penguin have provided a set of instructions for Mancala. It briefly guides you along the object of the game and how to win. These rules are found on the wall of the Book Room.
A description of how the game is played in real life is similar to that of Club Penguin's way. The instructions of the game from gamesmuseum.uwaterloo.ca should give you a handy start:
The visitor to the little Syrian colony in Washington street in New York City will often find two men intent upon this game. They call it Mancala. The implements are a board with two rows of cup-shaped depressions and a handful or so of pebbles or shells, which they transfer from one hole to another with much rapidity.
When the game begins, each player's score is 24. They each have 4 stones in the 6 boxes that belong to their side. The starting player must click on a 'hollow' (or circles as they appear in the game interface) from their row. This picks up all the stones in that hollow and drops a seed in each hollow in an anticlockwise direction, until the stones run out.
When the player reaches the end of the row, if there are stones left, the stone-dropping continues into the opposite player's row. This means that the originating hollow is always empty at the end of a turn.
The game will be won when a player has no more stones on their side of the board. The winner is the player with the greatest total of stones on their side! That's the basics of Mancala. However there are some important features to note.
Free turns:
As described in Club Penguin's instructions, a free turn is given to the player when a stone being dropped ends up in the other player's row (mancala).
Captures:
If the last stone is dropped in the opponents row and the hollow concerned finishes with 2 or 3 mancala stones, those stones are 'captured.'
Fun facts: The word mancala (منقلة) comes from the Arabic word naqala (نقلة) meaning literally "to move". The game was founded in Africa, and some speculate it to be the oldest 'board game' around, because it can be played with the sheer ground beneath us. Early Africans used to scoop out holes in the earth and use little pebbles or seashells as stones.