... here's how I made the earlier slightly tricky change.
Using this tutorial page I changed the front page of the site into a static page, which sat at "computerfloss.com/blog".
But I wanted the front page to be at the root of the domain, so I skipped over to this other tutorial page. This one guided me through the process of redefining the root of the URL -- a very nice little feature of WordPress -- so that the "/blog" part of the URL is no longer visible (to the public).
Now I can work on my plans to expand the site into something more than just a blog, using WordPress more like a CMS than a blogging platform. Watch this space for new content!