There are currently two versions of Google Sites - the "old" and the "new." They are slowly phasing out the old one, and the new one is still kind of in beta. The old version was GROSS and clunky and hard to navigate and even harder to manage, but the new one is slick and simple and easy! You can literally just drag and drop or copy and paste to build a website. The only limitation to the new sites is that it is SO new, there are some features they haven't yet worked in (ex: a blog-style page option, the ability to embed external gadgets/tools, etc).
If you are thinking of starting a class website, I would absolutely say to use the new Google Sites: sites.google.com/new
Click around in there, and you'll see how easy it is! They look really clean and professional, and they're super simple to add to/edit, etc. You can add a page for each student and share just that page with them (like a digital portfolio), or you can just use it for sharing. So many possibilities!