I am hoping to start a site up to inform people about music, all music, I am hoping to be able to put music up and let people listen to whole songs for free, but not allow downloads and anything of that sort. I also want to be able to let free members post music that they own to get the word out about they're favorite bands. If I do this, with full intention to give proper respect and credit the artists of each song and not allow downloads for free ro by charge, will I be legal or will I have crossed a legal line?

I believe copyright covers public performance of the piece, which you may well be violating. I'm sure someone more clued up than me will come along. I'm going to get this moved to a legal board, which is what this is more about.

Plus there is a (to me at least) very sticky and murky area of different people owning different rights. For example, the band may not mind if you put up the music, but the person who wrote the lyrics (who may not be in the band) may object to you putting up the words.