MicroSD card for music?

Hi, I'm going to buy a microSD card for my cel phone (LG8600) and I was just wondering the following things. I don't have a card slot for the chip on my comp (at least I think...), but I heard there is a pack that comes with a USB plug in. Is that true? And if I get one of these microSD's it says it holds music. Now does the mp3 player only take mp3s or will my wma's from my cds work on it as well? I don't want to go out of my way to get this until I find out these answers. Thanks in advance