Reply to Beginner garageband and keyboard to learn piano?

Hi all

I've left my decks at my mates house because we constantly seem to be having parties there so in the meantime I thought that when I'm at home I'm going to try and learn the piano and eventually try and produce something.

Can anybody recommend a cheap but effective keyboard I can use to teach myself via the garageband lessons?

Also, I ahve to KRK Rokits which I usually connect with my mixer via XLR. I've got them either side of my monitor now and would like to use them with my MBP. If I connect an XLR from the rokits into my audio out of my MBP I got horrible noise. Should I connect them via my audio 8 with RCA's instead??

Thanks in advanced