A very easy to read, entertaining as well as comprehensive guide - can't be beaten.
Great guides to help with those Japanese culture or business essays and classes. About 1000 other words or concepts (eg nemawashi and amakudari) are explained. Provide a solid insight into Japanese culture and a great source of vocabulary to impress your Japanese friends/business partners with.
Another useful (two part) guide explaining all those culture realted words and phrases. The link is to a more recent one part edition published in 1987.
I haven't read this yet but it's definately on my things to read list. Contains a good but not overly drawn out explanation of all things at the heart of Japanese pop culture, knowledge about which is essential to get by in Japan e.g. Doraemon(?).