1) To open the console, click Start, Administrative Tools, and click Active Directory Sites And Services. You have to use the Active Directory Users And Computers console if you want to create a GPO for a domain or OU. To open the console, click Start, Administrative Tools, and click Active Directory Users And Computers.
2) In the console which you opened, locate and right-click the site, domain or OU that you want to create a GPO for, and then click Properties on the shortcut menu.
When the Properties dialog box for the site, domain or OU opens, click the Group Policy tab.
3)Click New.
4)Provide a name for the GPO and Click Close.
5)The new GPO is linked to the site, domain, or OU which you chose in the MMC, by default. The Group Policy settings contained in the GPO are applied for objects in that particular site, domain, or OU.

otherwise, if you want to know about manage group policy, configure Group Policy settings and change the default processing order.. refer this web site:
http://www.tech-faq.com/implementing-and-managing-group-policy-objects-gpos.html