For my part, i've bought a book for grammar, and started with grammar in romanji.
As grammar is kinda easy toward french grammar, soon after I started learning writing system and words. I asked my dad for ajapanese / french dictionnary but, doesn't work it's really poor.
I found a wonderfull online dictionnary online, I'm learning a lot of things with it, even some expressions.
So, I read, I watch and I have this dictionnary open all the day long.
I do think the best way to learn a langage is first to be passionate with the culture. Not only manga or animes. Yes I watch, I read, and I even tl, but, through animes and manga I'Ve discovered a lot of japanese culture, like a part of shintou, ancient stories and else. Now, my next step is trying to put a hand on book for kids with japanese fairy tales and get even more culture. It's I think, the best way.
Sincerey,
Kanako