Upload nikon d3100 pics to macbook?

I just got a nikon d3100 and i realized it didn't come with a usb cable, so i went to best buy and bought "rocketfish" mini usb cable. It fits into both the camera and computer but then nothing happens. I tried turning the camera on while the cable is attached but again, nothing happened.

I'd say that's because you haven't installed the driver software that came with the camera - but you really don't need it anyway.

Most of us regulars here use and recommend card readers for upload. Readers aren't expensive and eliminate the need for extra software and that annoying cable. They're available where ever cameras are sold.