Personaly I wouldnt wear hard boots, these type are much better, [ below ], you will not need to wear then in, they are soft and comfortable, take two pairs if you have a back up car
Two pairs of thin socks are better than one pair of thick ones, blisters will not form as easily because your feet will not slide
Take breaks often, get air to your feet, and use foot powder, not creams, the drier your feet the better
at just over 3 miles an hour, you are not walking fast, but try not to go any faster thinking that you feel fine,... pacing yourself is important over a long distance
Walk with someone you get on with, it helps if you can chat away with others
...and well done, good luck
AKU Lerosa GTX Walking Boots | eBay
http://www.ebay.co.uk/itm/JOHNSCLIFFE-ME...2a1fb2bad8
A major part of survival is invisibility.