First of all, you need to make sure you have file and printer sharing checked in the firewall exceptions. To do this go to Start > Control Panel > Windows Firewall and click the Exceptions tab. There should be a check box next to File and Printer Sharing, make sure that's checked. Then, in the Control Panel window click Printers and Faxes. Right click the printer you want to share and click "Sharing..." - click the "Share this printer" radio button and choose a share name. To make it easy, also check the "List in directory" check box. Then go to your PC and open Printers and Faxes from the control panel. Right click somewhere in the windows explorer and go to Add a Printer and choose the option to search for a printer in the network or connected to another computer. Follow the setup and look for it in the directory, should be there. If it's not then find it using the 2nd option (looks like \\server\printer - where server is the name of the computer and printer is the name of the printer you entered previously) - let me know if that works.
Edit: Looks like I got beat to it!