Arabic is in my to be learned languages list (if I can advance enouugh in Japanese I'll go for the other languages)
for Japanese I suggest you first begin with learning Hiragana and Katakana. Tae Kim's grammer site is good to begin grammar. After you can study on
Kanji-Step - Japanese Language Resource Center to learn Kanji (also Hiragana and Katakana). I think it's a good site to see the reading and meaning of the Kanji with example sentences.