500g for mac

This hard drive does not show up on my powerbook. I have read other forums and it tells you to go go through disk utilities and partition, but  my hard drive does not appear. ??? Am clueless, any help would be appreciated.

Please read and follow the instruction on this article from this link, it will show you how to format the WD external drive to be working with your Mac computer:

http://wdc.custhelp.com/cgi-bin/wdc.cfg/php/enduser/std_adp.php?p_faqid=3323&p_created=1236623342&p_sid=kPmeK7Uj&p_accessibility=0&p_redirect=&p_srch=1&p_lva=&p_sp=cF9zcmNoPTEmcF9zb3J0X2J5PSZwX2dyaWRzb3J0PSZwX3Jvd19jbnQ9NzksNzkmcF9wcm9kcz0yMjgsMjYwLDIyNCZwX2NhdHM9MCZwX3B2PTMuMjI0JnBfY3Y9JnBfc2VhcmNoX3R5cGU9YW5zd2Vycy5zZWFyY2hfZm5sJnBfcGFnZT0xJnBfc2VhcmNoX3RleHQ9Zm9ybWF0IGZvciBNYWM!&p_li=&p_topview=1