a free website (ie not your own dot com?) - in which case why not go for one of the big ones like myspace/piczo/lycos tripod/ - they all have built in online webpage editors.
However, if you want your own site as a dot com or dot co dot uk, you would have to pay a company to host it and some of them like 1 & 1 offer easy online webbuilding programs with their deal. Or else you can build your site off line with free programs - here is one click here and then upload it to your online space. Look in pc mags as they often give older versions of webbuilding programs (check out netobjects fusion) for free too.