OS X server 3 veiwable from the internet

I am trying to get a OS X server setup so that I can see it from outside of my internal network.

I have got OS X Mavericks installed with the Server app installed as a VM for testing purposes right now, it has access to the internet and I can browse it from my local Macs on the network.

Now I want to be able to set it up as a basic webserver to which I can set up a website or a small cloud backup etc.

I have various Domain names which I use for my website and I could repurpose one of these or purchase a new one if needed.

I tried just turning on the Websites option which didnt work, I did have a play around with the DNS options adding in the IP of my domain etc but didnt get anywhere.

do I need anything else besides a Mac with OS X Server, Domain name ? or am I missing something completely?

I am fairly technical but this is a bit out of my depths here I have done my google seaching but eveything I seem to find is always based to set up a local webhost or within a corp network

if anyone can point me in the right directions I would appreciate it.

Adam