For a school, I'd recommend using a content management system (CMS). This is software that lets you create pages as easily as you might write an email, or post a question to this forum (

). Once created, the graphic design (colors, logos, fonts, paragraph style) is loaded into the CMS and all your pages automatically have the same look and feel. Although the set up can be difficult, there is no easier way to manage your site. Also you aren't stuck with some goofy address that's appended to Yahoo! or MSN.
There are a few free or open source CMS that I would recommend. My personal favorite is Drupal
http://www.drupal.org. But you might also like Plone or Typo3. I also know of one CMS company that works exclusively with schools, NovusCMS
http://www.novuscms.com. Their system will have a cost, but they set everything up to get you started.