whats it like to "walk"?

Piece of wee wee – why you ask? It's just a fairly steep hill with a few zig zag options.
I've never ridden it, run it several times and walked it occasionally.
Just put one foot in front of the other and you should be okay 🙁 😉

saw it in a book and it looked ace

It's a decent hill, but not a lot different to others around Edale. They all tend to be about the same height (Kinder plateau). Give it a whirl.
you could go up Grindslow knoll, then turn right and go round the ridge and descend roger… nice little walk.