I can't speak for online materials, etc., but my advice would be to find the local Japanese community doing study-abroad, learning English, etc., if there is one, and get involved. Making friends and using the language you learn is IMHO the best way to reinforce it and learn interesting things that you can't learn in class. When I was in college, I went so far as to get a Japanese room mate. That really helped my Japanese, and as he wasn't really interested in learning English, it worked great for the both of us!