Here are some resources to help you in your study of Japanese. Gambatte!
Books
All About Particles: A Handbook of Japanese Function Words by Naoko Chino
Essential Kanji: 2,000 Basic Japanese Characters Systematically Arranged For Learning And Reference by P.G. O’Neill
Basic Connections: Making Your Japanese Flow by Kakuko Shoji
Websites
Calger’s Anime Shrine: Japanese-English Glossary (Useful for vocabulary)
David Hallgren’s Japanese Page
E-Japanese
Expressions Used in Japanese Letters (Useful for writing to friends and host families)
Grade Breakdown Kanji Allotment (So you can study kanji at the rate of Japanese children)
Japan Zone
Japanese Phrase Book for Science Fiction Fans (But full of other helpful phrases to know)
Situational Phrases for Self-Introduction
Tim’s Takamatsu
Japanese Slang
Tae Kim’s Guide to Japanese
LingWiki
The Japanese Slang Jiko
WWWJDIC (Word search/translater/dictionary. I use this all the time)