Culture: Informative animes, Jdrama, Jpop, Jmagazines that can be ordered online or bought at certain bookstores, Jrock, newsletters, etc etc..... the best is knowing someone Japanese.
Language: Go to a college (not highschool, college.... they're more effective there) that teaches the language, buy their books for it (you don't need to be enrolled to the college to buy that book) .....
^_^ Trust me, the language books for Japanese can teach you by itself, you don't need a teacher around. (As I've learned) ... (Also there are games on the net that help you with your hiragana and katakana)
>_> As for how to find the culture on the net?
Google it. XD
Japanese is easy. But if you're scared to find it, then you never will.