How to set up each domain have own website

Dear Sir,

For Multi domains,how to set up each domain have own website.

I have point my domains at the MU install. all have the same IP.

Change the A records on every single domain to the IP of the MU install.

parentdomain.com is where I have wordpress MU installed
with the domain mapping and multi domains plugin.

How to set up own website for
domain1.com, domain2.com etc

Thanks!