This is an excelent clay kit to start out with.

You will be amazed at how smooth your paint will feel.
Start by tearing the clay up into a few small sections... Then put them in a cup of warm water. This will mean you can mould them easily so there nice and flat.
Wash your car as normal, De-tar if possible (you don't NEED to as the clay will remove most) it just means your not clogging the clay up with Tar.
Then on with the claying. BE LIBERAL with the Lubricant.. you can easily use a full bottle on one car.

Use very light/no pressure with the clay (as if your running a toy car over your paint.) Work in small sections, using smooth strokes until you can no longer feel anything on the paint and the clay bar glides.