You need to configure apache to use name based virtualhosting. See the below link for more documentation.
http://httpd.apache.org/docs-2.0/vhosts/name-based.html
You need to either use a web based admin program like webmin to do this or edit the httpd.conf file manaully to enter the virturalhost information.
Each website should have its own directory somewhere on the server that you set as the document root.
Once you have your domain resolving to the correct IP address then your set as far as zoneedit.