The opening – principles
There are hundreds of different openings to choose from for both Black and White. For the beginning player, it is more essential to understand the principles of opening play than to know specific variations. Here are four of the most important!
1. Develop: Invite everyone to the party. You wouldn’t prepare a twenty-course meal, spend the weekend cleaning, hire clowns and sword jugglers and forget to invite your guests, would you? In chess, before you try to checkmate, you have to develop your pieces and invite them into the action.

White has developed both bishops and knights and is ready to castle. Black has only moved pawns and the queen.
Whose party would you go to?

The advice to develop quickly doesn’t always apply to pawns. Pawns are often used to shield your other pieces, and determine the structure of the game. However, you often need to move pawns to allow your pieces to develop. On the first move of the game, there are only two types of pieces that can move: the knights and the pawns.

Diagram A. Diagram B.

1.e4 (Diagram A) and 1.d4 (Diagram B) are the two most popular first moves in chess.

1.e4 allows the f1 bishop to move, and 1.d4 opens up a diagonal for the c1 bishop. Both provide space for the queen to move. 1.e4 and 1. d4 are smack in the center of the board, which brings us to our next principle. 

2. Centralize. Pieces control more squares in the center of the board. Ever gone to dinner and been forced to sit at the edge of a huge table, so that you can only hear one out of the ten conversations? If you’re a social person, you probably hate this. Think of your chess pieces as social butterflies all of which want to be involved in as many conversations as possible.

Diagram A

Diagram B

The center knight in Diagram A. can capture any of the eight pawns, but the corner knight Diagram B is only controlling two of those squares.

3. Castle ASAP: make sure to keep your king’s cover on. Castling is one of the most useful moves in chess. You protect your king and develop a rook, all at once. Do it as soon as you can, especially when the position is open.

Black’s best move here is to castle. Otherwise, White will move his rook to el, with check and the Black king will be forced to move to f8. (Remember, you can’t castle out of check.)

Diagram A.

Diagram B.

In Diagram A, Black’s king is in good shape. In Diagram B, Black made the error of throwing his g pawn forward, leaving his king exposed to all sorts of invasions. Think of the pawns around your king as a shield. Don’t throw it off.

4. Watch your f7/f2 square! Don’t move your f-pawn unless you have a really good reason. The quickest mates in chess involve attacks on the f2 and f7 squares. Let’s review them so you can avoid them in your own games.
Fool’s Mate
The quickest checkmate in chess, the Fool’s Mate is a result of rash pawn play by White.

Lets go through Fools' Mate move by move:

Diagram A. Diagram B.

In Diagram A, Black’s king is in good shape. In Diagram B, Black made the error of throwing his g pawn forward, leaving his king exposed to all sorts of invasions. Think of the pawns around your king as a shield. Don’t throw it off.

Black responds with a good move, controlling the center and making way for the bishop or queen. 

C.

In Diagram C. White plays 2.f4, a terrible move, which irreparably damages White’s kingside protection. What can Black do now?

D.

Bang! Qh4 is checkmate!
Scholar’s Mate

Scholar’s Mate is a brutal four-move checkmate particularly prevalent at the scholastic level. It has led to more tears than fallen ice cream cones. .

A. B.

Scholars' Mate begins innocently enough. 1.e4 e5 2.Bc4 Nc6 (Diagram A.) White and Black have both played well so far, each player developing a piece and controlling the center with the e-pawn. In B. White plays 3.Qh5, an aggressive move with a terrible threat

Black, anxious to push the queen away plays the understandable but awful move 3...Nf6??

White now checkmates Black’s weak f7 square. Black cannot take the queen because the sneaky light-squared bishop backs her up.