Not knowing alot about Superkarts, i can't help too much.
I would start by looking at:
http://www.superkart.org.uk/
Try and get along to some meetings.
However, i would say that jumping straight into Superkarts is a bit of a radical step. In terms of safety and expendature. They are fancy bits of kit and by no means 'off the shelf'. Perhaps get to grips with a simplier, slower, cheaper machine for a year or two by way of preparation?
My two-penneth.
Cheers
Peat