FEET

Personally in the normal course of events I find feet disgusting but on the Camino they're pretty much THE most important thing. Every conversation will either start with or have a feet related element to it. So when it comes down to what you need to buy before you leave SHOES and SOCKS should be first on your list, even before you flights. One, you'll need to break your shoes in, and your socks too for that matter. Two, if youre having problems before you leave you'll need to CHANGE them.

SHOES
I went to a North Face outlet store and got a pair of their shoes. Id best describe them as a cross between walking boots and runners. All in all I was very pleased with them though a few tips

It rains in Spain (yes you also need youre factor 50) so make sure theyre WATERPROOF

Its also really hot in Spain so (in my opinion) you dont want anything too heavy

They will get more wear and tear than anything you've ever worn before so make sure they're DURABLE

Shoes are very much personal preference, I didnt want walking boots but others would swear by them so go somewhere where they know what theyre talking about, don't rush into a purchase just because the salesguys cute or insists they're the best on the market, basically; shop around.

SOCKS

I wore 1000 mile socks. Now while I've nothing to compare them to, having failed to follow my own advice and shop around, I wouldn't say they do exactly what they say on the tin. They make a very sweeping statement guaranteeing NO blisters and it doesn't hold up. I was very lucky with my feet - I only suffered from a few blisters, but my friend who also wore the same socks had HUGE problems with blisters. If you're in any way susceptible to them you will have issues at some point during the Camino, so be prepared. Find the best socks for your feet, bring medical supplies (more on that later), above all find what works for you. While some people swear by Compeed others wrap their feet in "electrical tape" before the blisters start.

Also DONT get ankle socks theres nothing worse than your shoes rubbing on the backs of your ankles.