Hmm, how did I get into J Pop? This is sometimes a question I find hard to trace back, but I believe the reason why I got interested in JPop in the first place was the Female artists. They are so cute!! And that's one reason why I like Japanese woman.. KAWAIIII!!!!! :anime:
First JPop Star I was introduced to was Ryoko Hirosue. Back in 1997 (ish) I read about her in an issue of Nintendo Official UK Magazine, and she was starring in a Japanese TV Commercial of StarFox 64. The editors fell in love with her and became obsessed with her. It's like Ryoko put a spell on them!!

Sadly I never got to hear any of her musics, but that was until recently when I downloaded some of her songs and brought one of her Albums. She is sooo sweeeeet I wanna HUG her!!
If anybody has a video clip of Ryoko in that StarFox commercial, please let me know!!
So basically what got me into JPop was Japan's cute Kawaii Female Artists. Some other great Female artists I discovered were.. BoA, Utada Hikaru (I heard she's releasing some songs in the UK), Morning Musume, Natsumi Abe, Mai Kuraki (I know some people say she sucks, but what the f*ck), Ayumi Hamasaki (although I don't really find her attractive but some of her songs are cool), ZONE, SweetS, ooooh too much else to list..
But aside from the Female artists, I heard some really good Male artists from Japan too. Mr. Children, TM Revolution, L'arc En Ciel, M Flo, Dir En Grey, SMAP, can't remember much else right now!!
2 sites I can reccomend are..
JPOP Music Forums
Check the Jpop Central Forum, There's a special thread where you can make requests.
JapanARadio
A JPop Internet Radio Station!!