The info below is for connecting to any windows computer with sharing enabled.
To connect to the PC throught OS X.1 first select the "go" menu in the finder and selcet "Connect to server..." (this is also possible by pressing command K [apple + k])
In the dialog that pops up, enter the appropriate info into the "Address" text box.
Here is the syntax.
smb://domain;username
assword@server/drive
Definitions
Domain - when you loging to your windows machine, is it on a "domain" if so you need this. If not, enter the smb share like this smb://username
assword@server/drive
Password - does not need to be entered if you don't want to. If it is not entered a dialog will pop up asking for it. (ex. smb://domain;username@server/drive notice the ":" symbol has been removed).
Username - like the password this also does not have to be entered. (ex. sbm://domain;server/drive notice the "@" symbol is also gone now)
Server - this one is obviously necessary
Drive - this is the sharepoint/volume/drive depending on your terminology to which you wish to connect, if you only have one share point on the computer, a drive is not necessary.