Film: Twilight Samurai. Fiction, but I believe paints a fairly believable picture of late feudal Japan, particularly in relation to a de-glamourised portrayal of the Samurai and the aplication of codified Bushido in their society.

Book: Essence of Ninjutsu by Masaaki Hatsumi: It never ceases to frustrate me that so many threads on this site crop up with ridiculous 'facts' about ninjutsu, and crazy misconceptions; when the acknowledged Master of the very arts under question is alive, well, and only to eager to share the truth of its skills and philosophy through his school and publications. The above book offers very un-fanciful insights into the history of ninpo, and where it has evolved to, along with debunking the nonsense that floats around as detritus from the 80's 'ninja boom'.
Good stuff.
Don't let the door hit ya' where the good lord split ya'