Grammar guides[/b]
http://www.guidetojapanese.org/learn/
http://www.imabi.net/online Japanese->English dictionaries[/b]
WWWJDIC
http://jisho.org/ <- Based on the same dictionary for WWWJDIC (appears to be slightly less updated though). Also, it lets you search for kanji by radicals and can show you the stroke order and other information about kanji.
http://www.alc.co.jp/ <-example sentences
Rikaichan and its modified version Rikaisama (Firefox add-ons)Text input[/b]
Google Translate <- Lets you draw kanji and also has a built in IME (an IME converts romanized Japanese into actual Japanese characters).
You could also download Microsoft's or Google's IME for Japanese.learning communities / Q&A sites[/b]
https://www.reddit.com/r/LearnJapanese/
http://japanese.stackexchange.com/questions?sort=votessome slang[/b]
http://www-personal.umich.edu/~weyrbrat/fanfic/anime/japanese/index.html
http://www.sljfaq.org/afaq/itee-sugee.html <- you'll see this a lot on this site
http://dic.nicovideo.jp/ <- Japan's Urban Dictionary/Know Your Memepronunciation[/b]
https://rhinospike.com/ <- audio recordings from native speakers
https://en.wikipedia.org/wiki/Japanese_phonology <- warning: very technicalbooks[/b] (I've never read these, but I always hear good things about them):
Genki I
Genki II
A Dictionary Of Basic Japanese Grammar
A Dictionary Of Intermediate Japanese Grammarmiscellaneous[/b]
http://ankisrs.net/ <- digital flashcard program. Download decks or create your own.
http://kitsunekko.net/dirlist.php?dir=subtitles%2Fjapanese%2F <- collection of Japanese subtitles for some anime series