Grammar...it's time

I had hoped that by living in Japan and cramming my head full of kanji and vocab, I would eventually absorb a decent amount of grammar. Three months later and this definitely has not happened. My grammar is deplorable; it's time to hit the books.

What is the best way to go about this? What are the notable books and websites? I know some basic stuff, but I'm still definitely a beginner.

Thanks much!