I think there is a big demand, but here's the situation ...
People want you to do it for free, which you'll discover that
it takes a lot of time and effort to not only design and
make the site (HTML and/or CSS), but continuous updates and
changes will take tons of your time.
So, you'll have to charge people and determine how long you
will support their site. Once money is involved, things can
get serious ... if you spend 10 hours making a website, you
would probably charge $200 ($20 per hour?). You probably
don't think it will take 10 hours, but add up your time and
you'll see it does. Will they expect you to make changes for
one year, two years, ten years .... for free?
Then, they might want server-side scripting, like being able
to process forms, content management. You'll have to know
PHP (or Perl), or sub-contract that part to someone who does.
Their site must look good with all browsers, so just whipping
one out using FrontPage or Dreamweaver won't do ... it might
look good with Internet Explorer, but not with Firefox. So,
you'll have to make edits, adjustments, and tweaking until it
renders properly. You better know HTML and CSS fairly good.
You'll need to do the graphics unless they provide them.
You'll have to have them find a webhost themselves, or will
you use your own credit card to pay for it? And what if they
pick a webhost that is difficult to work with?
A lot of thought needed before you decide to do this.
I suggest offering advice and answering questions to problems,
much like this forum. You can create your own forum using
something like this: http://www.phpbb.com/