You should just be able to plug in the SMC reader, and put your SMC in it.
If you have windows 98se or earlier you might have to download drivers, check the manual that came with the SMC Reader
You SMC Reader will be accessed as a "removeable media drive" in your "my computer"
If you have linux, besure you have 2.6.5 it likes USB devices better than 2.4 and mount /dev/sda1 (or similar depending on your hardware and os setup)
Then create the directory structure you need
GAMES
GPMM
GPSYS
GPETC
put all your games in GPMM and follow any additional instructions each game will give you in a text file
If you havent used your GP32 before, you are going to have to hook it up to your PC via the USB link and get it registered and freelauncher on it (unless you purchased one where this has been done for you).