First. Go to Google and search whats my ip. It will show u what the ip to your router is.
Second. Go to where ever u bought your domain from and Pont it to the ip you got for your router.
Third. Go into your router and into port forwarding(depends on router on what it is called). And forward to the ip of your servers local ip. And for the port use 80 on start and end port.
Then when u type in your domain name( www.metrikcorp.com is mine that runs on my servers in my house.)it should take you to your server.
P.S. depending on your internet provider and what kinda package you have with them. most internet providers block port 80 unless you have business grade internet.
You will also need a http server(I use apache2) on that machine.
Hope this helps