PNY MicroSD 2g

Hello,
I just got a PNY MicroSD 2g card. It came with two cards in it, a big one and a little one. I have figured out that the little one goes into the big one and then I put the big one into my computer. My problem is what to do next. All I want to do is listen to whole songs on my phone but it seems impossible with this thing. So what I'm asking is that someone tells me what do do after the card is in the computer. I have itunes if that helps at all..