I've been dabbling in Joomla for a while now, and I have very few negative things to say about it. It's relatively user friendly, tons of fantastic components and add-ons, and of course, it's free. Go to
Joomla.org. It's not rocket science to install, but the easiest method is to download the installer mod. Also, if you plan at all to have a user management feature, the Community Builder component for Joomla is an absolute must. You'll know what I'm talking about if you download it. Peace.