Chris's recommendation for Mark Richards' book is a good one - just don't try to follow any of the sketch maps!
My idea of the best long walk on Kinder is a circuit of the edges from just about anywhere, although Edale is nice (just don't expect quick service at the Nag's afterwards).
If you want something shorter than the 17 miles or so for the full circuit, one of the best short excursions is a climb up by the reservoir from Hayfield, past the Downfall to Kinderlow End, and back. Miles are easy on the edges though and it's worth doing the full round if you have time.
A new book about Kinder, with loads of history, photos and routes, edited by Roly Smith is new out - should be available from most quality local bookshops (and Waterstone's if you must).