Depends if you want off the shelf products or want something abit better
The stuff i use is from here
http://www.cleanyourcar.co.uk/ Its a really good site and the people on there are more than happy to help out with anything.
If you want to give it a decent clean then id start with these:
http://www.cleanyourcar.co.uk/washin.../prod_165.html
http://www.cleanyourcar.co.uk/detail.../prod_306.html
http://www.cleanyourcar.co.uk/polish.../prod_166.html
http://www.cleanyourcar.co.uk/wax/ch.../prod_337.html
http://www.cleanyourcar.co.uk/wheels.../prod_499.html
Everyone has their own opinions on what to use and how to do things but this will definatly get you started and will last the best part of a year just doing your scoob. In terms of best way to do it just take your time and make sure you constantly knead the clay, you can seriously damage the paint with the clay and make things 10x worse.