I did the london marathon in 2007, seems a long time ago now! The actual marathon itself was great, I got a place through a charity and they have people every few miles cheering you on. The atmosphere is great and they have bands playing outside pubs along the route. I took my earphones off because there was so much going on. The training in the last few weeks was horrific, finishing work and then heading out for a three hour run was a right ball ache.
In terms of distance, you just keep going a bit further every week and your fitness level just gets better do you are able to go fo