Note you can create a blog with blogger in about 1 minute.
It is VERY easy to use, and works like you want - type a heading here, enter some text here and so on.
You can have one person who updates it, or specify a group of people who can all update it.
New entries are added by date, and the blogger site keeps track of them all, adding the latest ones at the top and pushing older ones down the page.
You can add "tags" and the site becomes searchable. You can also have an index and updates are sorted by date (the site itself manages all of this).
While easy to do, you can buy a book that gives a bit more info of how to create and update you site (and promote it), and some of the legal issues. Book here
http://www.amazon.co....qid=1274180481&sr=1-5