I'm walking in March. So far, my planning involves reading this forum obsessively. Ha!
I'm focusing on five things over the next few months:
1) learning Spanish: I'm kind of obsessed right now!
2) packing list: reading lists here, going through what I have to see what will work (budget is small, so I can't purchase all new gear), weighing all of my stuff and tracking it on
http://geargrams.com
3) getting fit: walking, hiking, yoga. Trying to get to a normal BMI before I go. I realized that I was worrying about carrying an extra 100 grams in my bag when I'm lugging an extra 20 pounds on my body. Haha!
4) finding the right footwear: my feet are picky. I need a pair of low boots (high boots hit a pressure point on my ankles) with extra-wide toe boxes
5) saving money: pretty self-explanatory
I haven't really thought about the actual logistics of getting there, and route planning. I'll focus on that a little bit later.