Hey Lighty,
To be able to receive and decode commands from remote controls you would need an IR receiver, like this one:
This is an IC that does much more than a photodiode.
Signals from this IR receiver is digital, so you connect it to a digital input.
Read this:
http://www.arduino.cc/playground/Code/InfraredReceivers
or follow this thread for another solution:
http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1176098434