An excellent, super easy to understand, explanation of RSS. For me RSS feeds are a HUGE time saver. As far as RSS readers I am a big fan of Bloglines. I use Google Reader and Netvibes as well but until they both improve their mobile phone versions I will stick with Bloglines for collecting all of my incoming news and blog posts!
The creators of the "Common Craft Show" also have a great little video titled "Wikis in Plain English". Check it out!