Mac and Windows file sharing.

I can copy files from my PC to my macbook (OS X 1.5.2) very easily i just go into network and there my PC is, i can drag shared files across no problem. The problem starts when i want to copy files from the PC to the mac, i go into my network connections and i dont see anything except the shared folder thats on my windows pc. The windows machine is plugged into the router via ethernet and the mac is connected to the router through the wi fi. I have tried some of the tutorials on the internet but i dont think they are using leopard.

 

thanks i will take a look, sorry for such a newbie question