I'd have thought the starting block would be ideas from the client~
whoever your making it for, their thoughts and ideas as to what they
want the site to look like, colors, general layout, headings , etc...
then go from there....
but.....
coffeecup.com has many templates for free download~ though I'm
thinking you might have to have been a customer at some stage to access
them.. but have a look anyway, else a google for free templates
-might take a while to find true free ones, theres a heap of sites out
there, but the majority would prefer to sell them.. but there are
several with a good and free selection to choose from... try...
http://www.creatingonline.com/webmaster/templates/free_website_templates.htm
http://www.zymic.com/show_templates.php?id=2
and here's the coffee.....
http://www.coffeecup.com/freestuff/templates/