The Starting Place - A Web Server
Build Your Own
PiggyBack
Rent Webhosting
To have your web site be available you need a server that is always connected to the internet and always on, there are a few options:
It is entirely possible to build your own web server if you have the training and run everything yourself
You could also make use of an existing web service if the owner is ok with you using some of their bandwidth
The most popular solution is to rent web space from a Web Hosting Service and pay by the month, year or decade