newbie with cool edit

[jox43w]

iv had cool edit for a couple of months just playing about with it using standard sound card and a cheepo mike but now im used to it i want to buy some stuff to get dencent sounding trakcs problem is i have a laptop

samsumg vm8000
p3 1ghz
160gb harddrive

well basicaly i will be recodring hiphip over mp3 instrumentals

what sort of mike should i buy?
is my standard sound card fine? what diffrence will a better one make?

cheers