There is lots of information on this available on the web so if you are starting from a very basic knowledge I would suggest some research 1st ie google setting up a web server
for example http://www.linuxplanet.com/linuxplanet/tutorials/212/1/
some of the steps you will need to do off the top of my head and I will probably miss some or mention some that others wouldn't but ...
1. work out what you need it to have. ie does your site now or will it in the future require a database, php, perl etc etc etc
2. Find a spare box (If only hosting your site probably wont need to be too beefy)
3. install you fav version of linux (if a low spec machine go for a cut down distro). Include the stuff you required in step 1. ie at install include apache, php, db etc etc
- if already have a box with a base linux on it look at something like xampp (http://www.apachefriends.org/en/xampp.html
) to get all the web hosting basics on board.
4. configure apache and copy your site onto the box
5. check security (passwords on user accounts) iptables/chains (firewall)
6. put on a connection accessable from outside.
7. access and check everything is working as it should be on your site
also may need to do things like register domain name for the site etc.
configuring apache is another section although for basics you should just be able to put your site in the existing base htdoc directory which depends on distro and how installed apache etc