The pawn chess piece is by far the weakest of the chess pieces. However, there can be power in numbers. Try and promote these guys.
Pawn chess pieces are not very flexible. These pieces can only move forward and at a very slow pace. When a pawn is first moved from it's initial starting square, it can move either one or two spaces. However, after the initial move it can only move one space forward thereafter.
The pawn cannot move backwards. A pawn can move diagonally but can only do so when capturing a enemy piece. In fact this is the only way it can capture a piece. Pawns cannot capture pieces that are directly in front of it.
At the beginning of the game you have 8 chess pawn pieces available. However, this does not represent how many pawns are on a chess board at any one time. Obviously you can lose pawns and they may seem like expendable pieces.
What you may not know is that pawns can be promoted. In order to promote a pawn it must reach the end of the board at your enemy's side. At this point the pawn can be promoted to queen, knight, bishop, or rook.
In most cases a pawns promotion will be to a queen simply because the queen is the most powerful piece. So you may lose a pawn but gain a queen.
If a pawn is promoted to any piece other then the queen it is called under promotion and is very uncommon. Promoting a pawn take takes some planning but can be well worth it. A promotion could give you two queens.
Chess pieces can come in many styles so the pawn will look different from set to set. Staunton style is the one most people are probably familiar with since this is the tournament standard.