I have a Memoscan CAN OBD II U581 scanner
It is brilliant,once plugged in,it will ask for car make,then once it`s logged in to the car,it will give you the cars id (vin).
After that you can read any fault codes or cancell any if you need/want to.
It cost me £65 from e-bay.
As for obd II codes,I use this site.I know it`s American but the codes are relavent to us too.
I don`t regret getting mine.
My brother in law borrowed it when he went to look at a VW Polo.He found the cars id was different to the one that came up on the code reader.He did not say anything but did inform the Poloice.They have arrested the seller on car cloning charges.