Depends on the site, and how much free time to have to support him.
You might be able to get away with something like Jekyll, or else give your friend a template and a quick lesson in editing HTML (h1, h2, p, img, and a tags, plus testing and uploading should be about it...).
Option 2 is some sort of hosted CMS, with his domain name on the front - wordpress.com, posterous or tumblr, something like that.