The DSA has helpfully produced the attached set of flowcharts showing how you can obtain a full licence for the various categories of motorcycle, both currently and after the changes on 19th January 2013.
As I can’t upload the document here (.pdf files are not allowed for some reason!), here’s a link to it on my own website. http://www.justonemoremile.com/dsa-routes-to-your-motorcycle-licence.pdf
If you have any questions about the various licences, tests or motorcycles you can ride, post away and we’ll do our best to help! 😎