Mac or PC, it shouldn't make a difference when setting up the SD card. On the root of the SD card make a folder called
game. Put each folder containing a game or emulator in the
game folder. The .ini files, if you have any, need to be in the
game folder too, not the folder containing the game or emulator. I realize that this might sound a little confusing, so here is an example:
Let's say you want to put mame on your sd card. What you will want to do is place the
mame folder inside of the
game folder. Then you will notice that you have a file that came with mame called mame.ini. This file allows the game menu on the Wiz to track the emulator mame back to the folder containing it. So place the file mame.ini in the
game folder as well. Now, inside of the
game folder you should have 2 objects, the
mame folder and the file mame.ini.
Do the same thing with the rest of your games and emulators. If they have included .ini files then you will see a link to them in the game menu on the Wiz. Otherwise you will have to find your games via the file navigator on the Wiz. Alternatively you could install Win2X, which most people here seem to use. It provides a graphical interface similar to Windows in that you can put icons on a desktop and have windows that you can setup to display graphical links to all of your files on the Wiz. You can find that program here:
http://dl.openhandhelds.org/cgi-bin/wiz.cgi?0,0,0,0,7,286