Is there any particular reason why you didn't just create a new account and lable it "Gmail"? Also, go to Gmail and go up to settings and make sure you have pop forwarding on. While you are there, you will see instructions for setting up pop. It's incredibly easy.
basically you lable the new account Gmail, pop server is pop.gmail.com, outgoing is smtp.gmail.com, both require secure, no domain, enter your full email address(so include the @gmail.com) and your password. Have it save the password for automatic checking.
There is nothing Q specific, but here is googles instructions.
http://mail.google.com/support/bin/answer.py?ctx=%67mail&hl=en&answer=12103