How do i use it to copy pictures from my PC using my sandisk

Hi,
On the Windows system, the CruzerMicro appears as made up of two drives: A CD_ROM and a regular mass storage drive. If the letter of the CD-ROM is G, that of the mass sorage drive will be H.
You can explore both, but the one you want to drag and drop on (or Copy/ Paste to) is the second one (not the CD_ROM).
So you put files in the mass storage drive, safely remove it and plug it in the the MAC. On the MAC there will be only the mass-storage drive, because the other that appears as a CD_ROM on Windows is in fact a small OS that can only run on Windows (XP and maybe Vista).

However, it you have enabled the security feature of the drive (On Windows), you will not be able to open it on the Mac.

Hope it helps.