Japanese grammar is not too complicated. It doesnt really get much harder than the basics. The hard part is enriching your vocab and memorizing Kanji. For vocab and Kanji two very useful tool is Furigana-injector and Rikaichan (both Firefox addons). Especially if you want to learn from song lyrics. Song lyrics are not much good for grammar but for Kanji and vocab it is alright. A sempai from my study abroad program learned from imitating Japanese comedy (he is Indian and speaks in Kansai-ben
). So you never know.
Also watching older, slice-of-life anime can be good for your listening comprehension as well as they generally speak normally.