I listed many useful sites I found over time here: http://www.italki.com/groups/1810/topic/37478.htm I can also recommend http://www.guidetojapanese.org/learn/grammar. If I had to make a single recommendation, it would be this one.

こんにちわ you can use these sites, They are completely free: www.japaneseclass.jp www.japanese-online.com www.livemocha.com

久しぶり！ そっちに日本人はいないの？サイトを使うのも良いけど、実際に会話したり自分が書いたものをチェックしてもらった方が良さそうな気がするよ^^

You may already be familiar with these websites, but here: http://www.guidetojapanese.org/learn/grammar Tae Kim's guide to learning Japanese has been incredibly helpful to me over the years. If you are a beginner, then this may be a little advanced for you. Once you have acquired a fair amount of vocabulary, I suggest you take a look at some of his explanations of grammar... He has remedied a lot of my confusion in the past. I use LingQ.com for most of my linguistic pursuits.. I'm not sure about the beginning Japanese material, but it seems pretty worthwhile. I think that any exposure at all to Japanese will help you! I also like to read http://www.alljapaneseallthetime.com/ :) 頑張ってね！