Honestly it's really easy, it's just a case of keeping the panels moist and getting your head around the idea of rubbing a chunk of clay across your bodywork that's the hard part hahaha!!! Most clay bars will come in a kit with a lube (oo-er) anyway, expect to pay around £15 for a kit.
Check out
www.cleanyourcar.co.uk as they usually have a load of stuff on offer and also do sample pots on a lot of the polishes. I get most of my stuff from them and you collect loyalty points with each transaction that you can use to get money off future purchases. There's loads of other detailing shops about to be fair but they're probably the ones with the biggest range plus they have guides on there as well to download.