"Charles Kelly's Online Japanese Language Study Materials"
http://www.manythings.org/japanese/There is a multitude of study materials on that site, then another gazzilion of links to more stuff.
"Beggining Japanese I"
http://ocw.mit.edu/OcwWeb/Foreign-Languages-and-Literatures/21F-501Beginning-Japanese-IFall2004/CourseHome/index.htmOnline study materials for MIT course.
The only problem with those is that the sheer amount of stuff available might be offputting, making you think that there's no bloody way you could ever grasp something so extensive and complicated. Which is of course a false impression, japanese language is actually relatively simple in terms of grammar, and the hundreds(or more like thousands
)of kanji characters actually follow certain rules, making them easy to learn.
What you really need to get you going, is to buy a book which will guide you step by step, and let you wrap your mind around the basics.
Now, this one is what I've been using. It's really great and definitely worth the price.
http://search.barnesandnoble.com/Colloquial-Japanese/H-D-B-Clarke/e/9780415194785 (perhaps you can find it cheaper somewhere else, that's just the first thing that popped up in google)
I'd recommend signing up for JLPT lvl4 exam, as soon as you'll get about half way through the book - you can find links on that first linked site - which shouldn't take you more than a couple of months of dilligent study. It's not terribly difficult, and can give you both a motivation to learn and a sense of accomplishment when you pass.