Guitar preamp for laptop mic input?

[brand0nized]

Recently got my hands on Rocksmith so I can improve my playing, but I got it without the cable. It seems there's a mod that let's you use another input on your computer. My interface isn't 16-bit so it doesn't work. My mic input works, it's just terribly distorted and noisy.

How would I go about making a preamp to go between my guitar and laptop? (Please teach me about signals and impedance)

Sent from my LT22i using Tapatalk