Several months ago I presented the good walking guides you could find covering my favorite country (Greece). All the book series mentioned also cover other islands and/or interesting walking destinations elsewhere. But there is one series of books that (quite undeservedly really!) has not been mentioned yet (as they do not cover Greece). And that is the “Walk!” series by “Discovery Walking Guides”. I have good experiences with these (e.g their Mallorca North & Mountains guide is one of the best guide books I have ever used) and other current and previous offerings from Discovery, so I can only warmly recommend them:
BTW, the Book Shop has now been totally updated wrt the current Discovery guides and maps available.