Definitely check out concrete5 (http://concrete5.org http://concrete5.org). As others have mentioned, different systems are better for different situations, but

Definitely check out concrete5 (http://concrete5.org http://concrete5.org). As others have mentioned, different systems are better for different situations, but if you're talking about easy to use by non-tech people to manage an informational website, I have found Concrete5 to be better than the rest by leaps and bounds. The reason it works well for these kinds of sites is that it aligns with non-technical users' mental model of their website. Non-tech users don't think of their site as a template that displays content from a database, but rather as a bunch of pages with stuff on the pages. Most CMS's require users to go to an administrative back-end which shows a hierarchical sitemap of pages -- an abstract representation of their site -- and this is VERY confusing to most people. Concrete5, on the other hand, is based on the concept of content blocks on a page. So to edit a page, you GO to the page and add/edit blocks of content there. The blocks thing is great because it allows for different "mini-UI's" for different kinds of content. For example, to edit regular text, a standard WYSIWYG editor works fine, but if you want to add an image or a youtube video or a navigation list or a google map, it doesn't work as gracefully -- the block system means that different kinds of content can get different editing UI's specifically tailored for that type of content (for example, a youtube video just gets a textbox to paste in the URL, or a google map block presents fields for addresses, marker options, etc.). There are many web-based CMS's that utilize this approach -- Weebly (a YC company), WebVanta, SnapPages, Yola, etc. -- but I haven't come across an open-source install-yourself CMS other than Concrete5 which works this way.