Hi i have Successfully deployed the server with Linode LAMP Stackscript for a single domain name called domain called www.techiestuffs.com by Configuring Name-based Virtual Hosts
And I changed the DNS record.but after the DNS successfully resolved I am getting 500 internal server error.

I have uploaded the files to /srv/www/techiestuffs.com/public_html/ folder I think i should get the list of files in this directory whn i visit http://www.techiestuffs.com but getting 500 Internal server error.

Also I do not understand the Reverse DNS Lookup concept ? I could add only one site to that.

Can anybody tell what is the mistake i did.

The names resolve correctly, so it's not a DNS config problem.

So it's most likely a VHOSTS problem.

Did you restart Apache?

Did you run whatever funky Debian/Ubuntu apache control script to add a site?

Might help if you post your Apache and/or Vhost config files.

You only have to worry about rDNS if you're running a SMTP server.