Ultra Marathon Man by Dean Karnazes
This is one of my favourite books about anything, let alone running.
I'd also add Running Hot and Cold by Doug Richards. Not only is it packed with tales of running in places where you really shouldn't, Doug is also a Brighton fan (and my child minder's brother) and the chaps at Pitch Publishing are also local. You can order it via his website
http://www.dougrichards.co.uk