We'll be arriving in London, Heathrow Terminal 3 (next Thursday)and would like to take the Heathrow Express into Paddington Station. I understand that the train leaves from Terminal 4.

Is there an easy way to get from Terminal 3 to the Heathrow Express 'depot' at Terminal 4? Should we buy our tickets online now or purchase them at Heathrow? Any other advice regarding getting from Heathrow to central London would be greatly appreciated. :)

Still Running Late, Lesley Toronto, Canada