Connecting electric guitar to Macbook

Hi.

I've got an electric guitar from a friend but I don't have a Amp and neither money to buy one right now.
What I'd like to know is how to connect my electric guitar to my Macbook (it's not a Pro or a new Macbook) so that I can actually listen to what I'm playing in real time.
I know that the quality of the sound will be miserable but it's better than nothing! I've already bought a cable to connect my guitar to my Macbook and the jack to mini-jack adapter so I can connect it to the Line-in. I've already went to the Sound options and I've chosen Line-In as the input.
When I start Garage Band and choose a new real instrument track I can record what I play but what I'd like to know is how I can listen what I am playing louder instead of simply recording it.

Is there a way?

Peace.

I use this - POD X3 It's not cheap either, it will set you back about $350 or so.

But, isn't there a way to listen what I'm playing that doesn't involve spending money ?

jncunha said:

But, isn't there a way to listen what I'm playing that doesn't involve spending money ?

Click to expand...

Yes.

GarageBand Tutorial: Apple - iLife - Tutorials - Playing Guitar with Your Song