A site that's interesting to look at and not too complicated, with plenty to offer the reader, will keep people coming back for more, so many companies will require the services of a Web page designer in order to maximise their Web potential.
As well as artistic talent you'll need to be familiar with HTML, the coding language used by the Web, but there are lots of books on the subject available.
Approach design companies, who may be looking for people with web page design experience.
Another good marketing method is to contact companies already on the Net and (tactfully) offer to redesign their pages.
A great small business could be made of converting existing websites which are very poorly written. This is usually because the web site owners first language is not the language that the site is written in.