I'm planning my first coast to coast walk for a couple of us to do and am wondering how long it takes to prepare a walk typically.

Is it too ambitious to start planning in a couple of weeks and to set off mid April?

At the moment, I'm just browsing around, reading people's journals and looking at potential places to stay. It suddenly feels a little daunting having to buy maps (which one?!) and plan a route without knowing much about what lays ahead!

How long to people normally take to plan these things?