Kodansha International has published Yokai Attack!: The Japanese Monster Survival Guide, an English-language guide to the bizarre creatures of Japanese folklore by authors Hiroko Yoda and Matt Alt and manga artist Tatsuya Morino (Kibakichi).
It looks like a fun book. Cover art and details are now on SciFi Japan:
http://www.scifijapan.com/articles/2008 ... val-guide/