You could also use non-web based tools like Apple's iWeb of Adobe GoLive type applications. Create the pages off-line and upload them to a server host (assuming of course you have a domain name and server access).
I suppose you could also do it via a Wiki like PBWiki or Wikispaces...
I tried to get my 8th graders ready to do this a few years ago -- the platform (edublogs) was ready; the students were not. I am ready to try this again in the near future... Look forward to reading the responses you get from this post.
My high school is also looking to get a newspaper together and get it posted online. The students are interested in going online from the start but I suggested doing a hard copy first then we could go online once we have something.
Be sure to check out www.schoolnewspapersonline.com. Full disclosure: I'm co-owner of SNO. We have helped over 400 student publications make the transition to online publishing. We take care of the technical details so that you can focus on content and publishing skills.
We do indeed charge a fee to cover web hosting, template development and support. For free alternatives, check out http://myhsj.org/ and http://www.isonn.com/. In both cases, the sites will come with their ads.