For free learning resource:
http://www.guidetojapanese.org/I'd stay away from Rosetta Stone as a main source of learning. You could also just buy these three books:
A Dictionary of Basic Japanese Grammar
A Dictionary of Intermediate Japanese Grammar
A Dictionary of Advanced Japanese Grammar
Read those from page to page and you'll learn a lot of grammar and get a lot of good example sentences per grammar point.
However, first of all you should learn hiragana and katakana. Then learn Japanese grammar, vocabulary and kanji.