_tom_, least you will need like this is some kind of interface. That is with a Shure SM. These are dynamic mics and req. 48v Phantom power.
A usb or other mic NOT needing power could be used or go straight to PC but not a dynamic or condensor.
There are many many interfaces to acheive this, both usb and firewire. A free software program is easily available and most interfaces come with one anyway.
Personally (when my laptop, which has enough ram/memory etc. gets here from Texas with missus) I am gonna use a Line6 toneport UX2 (which has 2 phantom power outlets) to record direct from amp.
However even cheaper solutions are there.
Tascam,Line6,M-Audio etc. all produce phantom power interface devices.