I am planning to do the Way in May going from Bath to CC - Are there any guides that do the South to North walk as the ones I have seen all do N - S.

Also what's the most strenuous bit?

I did this walk last January, and found the worst part was the last couple of miles into Bath, because of the stste of the footpaths which were extremely muddy. This may be different in May. After you are past Bath racecourse, this problem eases, so don't get too disheartened at the start!

Most of the walk is a series of ascents and descents, and although one or two are worse than others, there's nothing too serious.This was one of the best walks I have ever done, and one that I intend to do again in the future. I'm sure you'll enjoy it.

I don't know of any south to north guides.

Try "The Cotswold Way" by Kev Reynolds ISBN 1-85284-049-8 published by Cicerone.My copy dates back to 1990 but it should still be in print.