How do I formatt an S/D card for music ( forMP3) on my computer???

I recently bought an Audiowave ACD-8016 Car radio cd/mp3/wma player with USB, MMC & SD card reader. I also bought a playdot.com 2 gb mini SD card and I need to know how to formatt it to accept music from my Compaq Presario laptop computer. I have used Freerip to convert my cd's to MP3 for mat and I am now ready to install this music on the SD card. Can anyone give me a simple answer as to HOW TO DO THIS??? PLEASE thank you