-First, you need to connect the LCD to Arduino / Protoshield. There are several tutorials available about this topic, an example:http://www.ladyada.net/learn/lcd/charlcd.html
-Connect one potentiometer to pin 3 of the display like as you can see in the tutorial above to have contrast control, the other potentiometer is necessary to connect to A2 analogic pin of Arduino, we will use it to read an analogic input 0-1023 used to transform in the interval chosen inside the Arduino sketch.
-Connect on on/off switch to pin 15 of display, this is for a backlight turn off to cheep battery power (my timelapse are about 5 h of camera shot)
-Connect another switch that will use to power supply. About power you can choose different method to supply, USB direct connection if you are near the camera, one 9v battery connected directly to Arduino.
My goals now is to realize a power supply like show in this useful instructables:http://www.instructables.com/id/The-Arduino-AA-Undershield/
-Connect one micro button and a resistor to Arduino pin reset to bring out the command.
-At the end connect on IR LED to pin 13 and one resistor (100 ohm)