Ooooh, I've just thought - here's my offer;
The Mercian Maquis - see Amazon link
http://www.amazon.co.uk/Mercian-Maq...=sr_1_1?s=books&ie=UTF8&qid=1328723384&sr=1-1
Synopsis
This book deals with the shadowy Auxiliary Units, formed in Herefordshire and Worcestershire in 1940, which would have operated behind a German invasion force advancing on England's industrial heartland. Organised into patrols of about half a dozen men, their role would have been to carry out acts of sabotage and terror whilst the Regular Army regrouped for counter offensives. From carefully camouflaged underground Operational Bases liberally supplied with explosives and arms and constructed in woodland on high ground, patrol members would have set out at night to harry the invader. This was to be done in the knowledge that they and their families risked summary execution if captured.
I thoroughly enjoyed this book.
Off topic, but there's one of those shelters near me, and I've been inside it. Absolutely fascinating. Doubt I could find it again though.