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Arduino, Multiplexing, LED's and Resistors. Answered

Ok ok. I'm rather new to electronics, had very minimal use with resistors. I could probably work out which resistor I needed for a series LED connection, but because it's multiplexing, it stumps me on whether it is a series or parallel connection. Pretty much, I'm wanting to run a 5x5 matrix, using these leds (information on it there), through my Arduino, I know some users here have Arduino, but the factsheet, with voltage and currents information is there.
I am wondering, what resistors I'm going to need to use. If you could also say how you calculated that, it would be splendid. Is multiplexing connecting LED's in series or parallel?

I noticed the led link didn't work, but they have the following specs: How bright/dim is 3mcd? I'm assuming it's pretty dim...
# Luminous intensity: 3mcd
# Forward voltage: 2.1V DC
# Forward current: 15mA


need to hookup some leds that will flash in several directions. looking for some type of code for the arduino that would point me in the right direction.i'm able to get the ights to flash but not alternate.I've been to some of the libraries but unable to pinpoint what i'm looking for.

You do know how to turn on/off individual LED's don't you?

well, the simplist way is to put a resistor on all of the output pins that would be half the value of the normal single resistor in series. So no matter what LED is lit up you have the full value of the resistor. in charlie plexing whenever an LED is lit up it is in series with 2 I/O pins and the 2 resistors mentioned above.

Remember this is multiplexing not charlieplexing.