I will answer your question in two ways:
1) If you tell us what Distro you are using, and whether you are running GUI or CLI, and if you have Apache or Apache2 and what you have tried so far and the results we will help.
2) If, on the other hand, you fire generic questions into the forum without any attempt to help us to help you by giving information on platform and OS, and no evidence of any attempts to find out for yourself with Google, then we will likely either ignore you or flame you.
For the Web Server (AKA Apache) try here: http://httpd.apache.org/docs/
For DNS Server try http://tldp.org/HOWTO/DNS-HOWTO.html
Remember, nothing in this life is free. Linux costs nothing to buy, but you have to make investments in your own knowledge. Just posting "help" without trying to solve the problem yourself is like sitting on the street corner begging. This is not intended as a flame, more as the response of a parent to a erring child, please take it as such.