Recording questions, mainly about cables. Options

Hi,
I'm a young musician, and looking to start recording some of my music, I do mainly vocals and electric Guitar. I'd be recording on a G4 400 mhz, 128 ram.
Anyway, I've been searching around and am wondering what sort of equipment I'd need to record to the sound card my computer came with until I can afford something more expensive, looking into soundblaster live.
What sort of mics should I get, and how do I hook them up to my computer, I assume the mics would have Midi cables on them, and those won't plug into my audio in slot obviously. Are their midi-to-normal audio in adapters availible? Can I hook up more than one mic to my audio In?

Any help would be great,
Everett