Alright, first of all you will need to find a web server service such as apache or microsoft IIS. You will have to install and configure this correctly to handle HTTP requests.
After that assuming you want a dynamic capabilities you will want to either choose PHP or ASP, my preference would be PHP. You will then have to install and configure PHP to work with apache. You may also want some database software such as mysql.
Once you get your server working locally you will have to configure your router to port forward all of the packets with inbound port to your computer. Assuming you have a dynamic IP you would then need to register and set up DynDNS or a similar service to map your dynamic IP to a private IP.
Not to hard actually, hope I didn't give to much away. About links, just google for the software I mentioned.
A+, Network+, MCTS(70-620), Security+, CCNA