Nigel,
Pre-made templates can be a great thing. Often, they provide a
fabulous starting point for your ideas, the creative spark that can get you
going on a site. You have to be careful though to find a template within
your skill range. For example, many of the template on this site (which is
an affiliate for templatemonster.com) come with the HTML and some Flash, but
the original source is in Adobe Photoshop. If you're not familiar or don't
have Photoshop, it will be difficult to manipulate the images and do things
such as change button text. You also have to be careful because some of them
are designed to be purely flash sites, which can be difficult to work with
unless you have experience with Macromedia Flash. Templatemonster makes some
of the most beautiful templates I've seen on the market, but they usually
require a skilled graphic and layout hand in order to adjust them exactly as
you wish.
Hope this helps,
Mark Fitzpatrick
Microsoft MVP - FrontPage