You'll need an interface of some sort.
I use a cheap M-Audio Quattro USB. They make others as well, both USB and Firewire.
http://www.midiman.net/index.php?do=...bileinterfaces
Someone else will probably suggest another manufacturer.
Simplified, you want to connect your guitar into your rig and send the output from your rig into the interface which then sends it to your laptop.
If you use a PODXT, you can connect the USB out from the PODXT directly to your laptop. You would just need the USB drivers for the PODXT.
What is your guitar rig that you want to record with?