Hi, I'm new on here and would love some advise from experienced runners. I just started running last week, and have a place for london marathon in April 2012. This gives me just under 6 months to train. This is probably absolute madness as I'm finding that I can't run for much more than 5k at the moment, but I'm hoping with the right training I would have just enough time to be prepared. I'm 20 years old and am not overweight - hopefully this'll be an advantage! Thanks in advance!