Best Japanese textbooks, ever: Genki - An Integrated Course in Elementary Japanese
And considering the age range of these forums, many of you should consider the
Jet Programme.
Edit: Almost forgot
MSN-Mainichi Daily News. The WaiWai column is particularly funny!
Also, read Japan: A Reinterpretation by Patrick Smith. It's rather harsh, but if you're going to be learning the language, you might as well educate yourself about the culture, so you're not one of those "Everything I Need To Know About Japan I Learned From Rurouni Kenshin" people.