Identifying Pins of an Unknown LCD
This is a pretty common pinout for an LCD. You can be pretty confident that it uses the Hitachi HD44780 chipset. The LiquidCrystal library should be able to drive it without any trouble. The K and A pins are just backlight power pins. 

Any digital pins should work... just make sure you connect the pins to the LCD the way the comments in the example suggest. You just need to map the pins you are connecting to the signature of the constructor being used in the example.

lcd(12, 11, 5, 4, 3, 2); 


is using the constructor from the library docs that goes with:

LiquidCrystal(rs, enable, d4, d5, d6, d7) 


You know this by counting the number of arguments. So in the example:


Digital 12 == RS     == LCD pin  4
Digital 11 == Enable == LCD pin  6
Digital  5 == D4     == LCD pin 11
Digital  4 == D5     == LCD pin 12
Digital  3 == D6     == LCD pin 13
Digital  2 == D7     == LCD pin 14


You obviously also have to connect LCD Pin 2 to 5V and LCD Pin 1 to GND. You may also need to hook up a potentiometer to LCD pin 3 to adjust the contrast. Which may be the problem you are describing in your comment to me above. There are literally hundreds of tutorials on line about this, use the google :).