Road Tax for 2012 can be renewed online from today.
You will require the following details:
Registration Document (Log Book).
The last three digits of your ID, Alien Card or Passport number. This is the one shown on the logbook.
Insurance certificate may be required if cover commenced recently and has not yet been entered onto the database.
You must have a valid Test Certificate (Bi-annual Roadworthiness Test) if your vehicle requires one.
Details on other ways to renew can be found here.