Singing/ Making Music on the PC

Hi Everyone,

I'd like to sing and create songs on my PC by processing my voice, synthesizing tracks, mixing stuff, but not just at a Karaoke level, but as close to a professional level as possible within my $200 budget so it sounds at least as good as Owl City (at least music-wise).

What software do I need to achieve this? What mic would you recommend? My budget is $200 max (I think the emphasis of this should be on a high-quality mic, not the software, right?)

And do I REALLY need a sound card for this or will my motherboard's on-board audio be enough?

Thanks in advance!