Summarize:

The standard Battleship game set comes with two boxes, one for each player. Each box opens to reveal two grids, one on each inside surface. If your game set does not include two boxes, plenty of red and white pegs, and at least six ship pieces, it will be difficult to use. Try playing on graph paper instead, as described below, or finding an online version of the game. Ships come in various lengths, taking up a different number of squares on the grid. The two players should have identical collections of ships. The following is the typical list, but if you don't have all the pieces, just make sure both sides are even: A single ship five squares long (the aircraft carrier) A single ship four squares long (the battleship) Two ships three squares long (the cruiser and the submarine) A single ship two squares long (the destroyer) With the boxes open, and the players seated across from each other, each player puts his ships down on the lower grid in front of him. Follow these rules to determine where to put your ships: Ships can be placed horizontally or vertically, but not diagonally. You must place all five ships on the grid. Every ship must be completely on the grid. No ship can hang off the edge of the board. Ships cannot overlap each other. Once your ships are placed and the game has begun, you are not allowed to move your ships again. If the two players don't agree who should go first right away, flip a coin or decide in some other randomized way. If you are playing multiple games in a row, consider letting the player who lost the last game go first in the next one.
Give each player a battleship box. Check that all the ship pieces are there. Have each player secretly arrange their ships. Decide who will play first.