Connect Roland Drum to Macbook Pro

I am new to to GB and i want to learn how to
1. connect my electronic roland drum directly through it's module or an amplifier
2. Record my playing while having a song played at the same time
I currently run a Y- cable to my amplifier to connect my ipod while drumming. I tried connecting a male-male cable from the headphone jack of my amplifier to my mac (i thought w/e i heard on the headphones would be recorded, but it's not. I guess i had the wrong input)
Any suggestions?