And to answer the other question, no it's not simple, it's quite a large learning curve and does require some php editing at times. If you're versed well in html and css then you shouldn't have too much difficulty with a CMS.
CMS stands for Content Management System and basically allows you to make articles rather than website pages. Contains all things in one setup that you don't really need to alter themewise just add new content. If you have worked with Wordpress at all, that is similar on a more scaled down level.
If you're curious, one of the best ones out there right now is Joomla which is pretty powerful, but do realize that it's not something that you can just load up and go, it takes a bit of installation and such. Usually if you have a CPanel on your server it comes with that in Fantastico.