have a looka at one of ray mears books, they have some nice photos. also the sas survival book by lofty wiseman has plenty on food. i also have a book that i got in waterstones, on edible plants thats quite good, it has a use/how to use section for each plant. i'll look up the isbn when i get home and post it here for you. did you mention rowan? you can make jam out of the berries.
steve