There is a website where you can download many, many things, like books, videos, and dictionnaries. It's all in Rapidshare or MU links though, so not everyone will be happy with it.
This one:
http://nihongo-dekimasu.blogspot.com/
I will try to slowly upload things by myself ( I won't upload everything, because even though I'm very fond of sharing, I am also a language instructor, and I have high respect for other teachers work. So, no private 材料）.
