I got my stuff from a local store in the UK -
http://www.maplin.co.uk but I think Radio Shack is the US equivalent.
The instructions should be pretty straightforward and I'm sure the guys at Radio Shack will be only too pleased to provide help on what you could use for switches, LED's etc.
I used a 9v battery as the power supply and the online program worked out the resistors and the wattage of the LED's for me. I fitted it all to an old set of headphones with a small rocker switch to turn it on.
The hardest part for me was having the webcam just recognise the LED's and tune out the background light.
Have fun and keep us posted on your progress.
Alex