[jhautz]

where do you solder these caps? I was wondering if they could be put in near the plug end of the power wires, or do they need to be as close to the board as possible, or doesnt it matter?

I'm assuming positive lead to positive wire and negative to negative. That brings another question... How do you know which lead is positive? If I remember from way back in high school electronics class on capacitors the positive lead is a bit longer than the negative, or are they marked somehow?