Wordpress.com on the other hand is aimed at anyone who can type on a keyboard and provides free hosting. There are some limitations to the .com version, the most significant being that you can't really add any custom scripting (server-side or client-side), you are limited to the Wordpress.com Template Library (currently over 260 templates) which can only be customized to a certain extent, and there'll be a "Blog at Wordpress.com" footer on all your site pages along with a credit for the theme you are using. For most people, these are perfectly acceptable trade offs for a platform that allows you to build a website and publish it live to the interwebs only minutes after you get started (you'll of course want to spend some time putting your content together but your site container can be published very quickly). Until recently, a very significant limitation to the Wordpress.com platform was that you couldn't really do any sort of e-commerce beyond sticking a PayPal donate button on your site. The introduction of the rather excellent Ecwid Shopping Cart to the Wordpress.com platform has eliminated this limitation.
Perhaps the best thing about Wordpress is the enormous amount of online support documentation. There is literally no question that you are likely to ask that isn't answered in the voluminous Wordpress support pages. If you're just getting started, check out the excellent Learn Wordpress.com sub-site. In short, you just sign up for a free Wordpress account (in which you can create multiple, separate Wordpress sites), pick a template, add your content, and publish (Wordpress provides a free domain that'll look something like "sitename.wordpress.com". Now, if you're using Wordpress as a means to communicate the elementary school soccer team schedules to the other parents, you can hang tight with your free domain. If, on the other hand, you'd like to have a custom domain like "bobsawesomewebsite.com", you'll want to secure your domain with a domain registrar and then connect that to your Wordpress site. Wordpress can register your domain and directly connect it to your site in one fell swoop, however, I always recommend that the domain registration and website hosting be handled by different entities (just in case you want to move to a different host down the road). Wordpress gives you the step by step instructions on connecting your domain to your Wordpress site. Customizations such as this will cost you a tiny bit of money. Registering your domain through Wordpress will cost $18 per year. If you've already registered your domain through another registrar (e.g., Godaddy), you can connect it to your Wordpress site for just $13 per year. In this case, you'll be paying your domain registrar fee (e.g., about $12-13 per year through Godaddy) plus the Wordpress domain connection fee. Even then, you're only looking at about $2 per month for your website which is about as inexpensive as it gets. Ready to give it a whirl? Start here: Wordpress.com.