Ektron has put out a solid whitepaper that's worth a read if you are looking for a content management system.
It's aptly named “The Essential Guide to Selecting Your Web Content Management Solution” and is available for free download (link below).
Some of the topics covered include:
Even though this is written by a vendor, there's a ton of great content in it and if you are looking for some tips and advice, I recommend giving it a read. The whitepaper itself is free, you simply need to fill out a quick form to get the download.
You can grab the whitepaper here: The Essential Guide to Selecting Your Web Content Management Solution