Yes, it might look difficult at the beginning, but it is very easy.
First important thing: booking for European trains is usually possible up to three months in advance before departure date. So you still have to wait until February 2013. To get an impression of possible ticket fares, just out try a date in November.
Berlin - Paris
: easy as e-ticket here. Also the best and lowest prices as it is directly from the German national railway (which also run this CNL night train): rail.shop/bahn
Paris - London
: also available as e-ticket via: rail.shop/beurope
London - Holyhead
: again easy as e-ticket via www.nationalrail.co.uk
If you have further question, just let me know.
Using trains in Europe is very easy and relaxing. Just go to the railway station where you will find big displays showing you the departure platform (or ask the service staff if you feel unsure).