Your question is unclear.
Are you wanting to
- Set up the nameservers on your new 12.04 (let's call it monkey)
server so monkey can resolve addresses by using a specific
nameserver (like Google's DNS).
- Point your domain (e.g. example.com)
to your new server so you can access it by browsing to
In the case of the former, you will need to edit /etc/resolv.conf and add the nameservers IPs to the file. If you wanted to add Google's DNS to your list of DNS servers, you'd add 126.96.36.199 and 188.8.131.52 to that file.
If you're trying to point your domain (example.com) at your new server, you will need to refer to your domain registrar's documentation. Who did you register the domain with? Joker/GoDaddy/etc?