Challenge BattleChess for a game and play free chess games against the computer. As a beginner in chess you probably will get crushed. But this program is not very strong. Play until you can beat it then move on to others.
Control the center and don't put your pieces to the edge of the board. Push only the center pawns (e- and d-pawn) in the beginning to control vital center squares.
After this get your pieces (knights, bishops) out quickly and castle early to bring your king into safety.
Try to win material (pawns, pieces) then simplify and trade of pieces to enter the endgame. Then create a passed pawn and promote it into a queen. After this you can checkmate the king easily as you are a queen up. In this case your opponent usually resigns.
To make a move - Just click on a piece, then put it where you want it.
To castle - Click first on the King, then on the Rook.
Each move is shown on the right hand side. This helps you to learn chess notation.