The parts supplied suggest 3 arrays of 2 LEDs. In a series array, all (both?) LEDs will carry the same current.
Without knowing the exact parameters of the LEDs supplied, it is difficult to know what numbers to put into the calculator in Rex's link above, but at a guess, if the LEDs drop 2.1 or 2 volts each, and need to run at about 20mA, then on 12 volts the resistor will be about 390 ohms (orange, white, brown) or 470 ohms (yellow, viollet, brown). If a 6 volt supply, 100 ohms (brown, black, brown).
The link also suggests the appropriate circuit and gives as an option, the resistor colour codes.
Resistors dont care which way round they are connected. The D in LED stands for "diode", and, since they have very limited reverse voltage tolerance, they must never be connected the wrong way round, as they will protest by dying.