The far-Eastern Rakshasa is yet another type that touches on some vampiric traditions.
I'll second the Wikipedia recommendation. Lots of people poo-poo it because it is croud-sourced but it is usually an excellent starting point.
I have an old yellowed copy of a mythological dictionary that was a valid attempt. Here is a modern reprint --
http://www.amazon.com/Dictionary-Cla...2257891&sr=1-1 .
Another excellent source of "real" mythology is Joseph Campbell but his works are more like episodes of Connections than an encyclopedia.