Training going well, but doesn't make up for fact I'm a marathon virgin!

I have a confession to make. I've never run a marathon before!
However, I've been running regularly for a couple of years and doing much longer distances over the last few months. The furthest I've run is 18miles, but I'm building up stamina nicely.
Over the last 3 days I've done 3 half marathons (14miles, 16miles and 14 miles). Apart from feeling achy, my 39 year old body is holding up well.

I'm under no illusions how tough this run is going to be and I'm training hard for it. There is a long way to go to get fit enough for this run, but if I stay fit and healthy and take the correct advice, I will give it my best shot.
Thanks for all the very supportive comments and e-mails so far.

I'll post some political stuff soon, but the key political blogs will come during the run itself fro maximum impact.
I'll also share some campaigning ideas that I'm finalising at the moment.