Sustrans:
Charity promoting walking and cycling. Their website contains maps of the National Cycle Network as well as hints and tips for how to incorporate more cycling and walking into our daily lives.
http://www.sustrans.org.uk/
Rail Europe
Website helping you to book train journeys in Europe. https://raileurope.co.uk/
The man in seat 61
Useful guide to how to travel by train in Europe. https://www.seat61.com/