I use Merrell brand hiking boots. Never failed me yet. DH swears by wearing two pairs of thick socks. Wear your boots in first, eg wear as much as possible before you go. Pack compeed plasters, just in case.
Bought my Merrells from Milletts, for our honeymoon nine years ago. Still going strong.
Is good to wash feet, dry them (and let them dry before putting on socks) when walking nd you know you stop for 30-45 min I like to take boots and socks off to air them and walk bare feet on a bit of a grass if possible
Go to a proper walking shop and explain to them what you will be doing. At our local shop (we are in the Peak District, what about you?) they will measure your feet properly, they know which brands of boot fit which shapes of feet best and will advise. They have a little slope, so you can see how the boots feel going up and down hill. I have extremely wide feet and have leather Scarpas. They have been fantastic boots, extremely supportive and v comfortable and much lighter than I expected leather boots to be. Buy the best boots you can afford. Wear the boots while you are training so they're properly broken in and your feet are used to them by the time you do your walk. And wear proper socks, too. Take your training really seriously. Do lots and lots of practice walks, short ones initially, then building up. Try and do some walks on similar terrain to the 26 miler - doing lots of circuits of a flat city park is no preparation for hillwalking. Even if it involves having to have a weekend away, it's worth it. (my dh used to be a Mountain Rescue volunteer; they would despair of people turning up underprepared, then getting injured, or having to drop out due to exhaustion -> whole team having to drop out). PS good on you, that is a big walk! I hope it goes really well. When are you doing it?
Its not til 9th oct and i've been doing some practice walks for past month or so(building up the lengths) did 6 miles in flip flops and 9 miles in little plimsols and would like to get some proper footwear before my next go!
And thank you for the encouragement too, people seem to be laughing out loud and dismissing it when i tell them its so annoying!!
Just to add to the good advice: the best walking/camping shop for footwear is Cotswold Outdoor.
They're the only ones who specially train their staff to fit & reccommend footwear for all types of use.
They should take at least an hour with you. Take a whole bunch of foot measurements, ask you how & where you intend to use them. Ask about any ankle/knee/hip issues. They'll use extra insoles, heel support, tongue thingys (my knowledge is dwindling now!) to get a good fit. They can even stretch bits (I have a wide fore foot, for example).
They'll reccommend socks & tell you how to care for them. And they'll give you as much aftercare as you need.