A common thing in the last few years has been to use CMSs or (content management systems) which are basically software (files linked to a database) that sit on a server and display your website, giving you the option to change the content of the pages dynamically. You can use modules (more files that add tables to the databases) to extend functionality, and themes or templates (the looks) to change how your entire site (or part of it) looks. Most of the CMSs people recommend here use PHP (most migrated totally to PHP5) as the language and mySQL as their database of choice.
Drupal, Wordpress, Joomla, Xoops, Typo3 (in my order of preference these are the ones I've tried) you will have to get a webhost with PHP5 and mySql (most of them do right now). There are many tutorials for both on how to setup the sites. Maybe look for webhosts that have some sort of automated installation scripts (many have fantastico, some like dreamhost have their own); that is the easiest way of getting to know these softwares and selecting one. Install them, test them, and find which one you might be comfortable with at the end.
Wordpress I found to be the easiest to setup and run, with an amazing quantity of themes and modules. Very stable.
Drupal is my choice, it doesn't have the best looks off the bat, but if you are planning to grow your site in the future and are willing to learn, this might be the option. It is for me anyways.
Joomla I found to have the best looks right away; but, although it has many modules, if you want to extend it in the future it might become pretty complex.
