One of the easiest ways to add content to your site is via a "blog".
What is a blog? A blog is a term used for writing regular entries to your site, the entries are usually events, notices, news, or even instructions (like the below blog entries).
Why use a blog? A blog is MUCH quicker to express a thought on your web site than creating a web page that has "proper" navigation (menu structure to find it), and a proper page layout. A blog is usually just a quick thought, although you can make your blog entries fully match your site and you can even put links to them in various places.
What about RSS? RSS - Really Simple Syndication - Is a technology used to get "news" from your site, like what's new, what's changed, why should I come visit your site again to read more information than the headline, etc. Blogs are easy to export via RSS and a very common media people read via RSS.
How hard is it to blog? It's about the same as using a word processor. Everything is web based and you simply click add entry and start typing - Watch the video for a better explanation: