I installed a SharePoint on single machine with Active directory. The domain title is xxx.com. Then i produced a SharePoint site with default port as 80. I'm able to now access this SharePoint site by typing in http://xxx.com. Now I must create 2 more websites which I must call as http://intranet.xxx.com and http://extranet.xxx.com. How do i make this happen ...??

I'm using home windows 2008 R2 and SharePoint 2010 Enterprise edition. Greatly appreciate should you could direct me to the helpful assets.

Thanks ahead of time...