A good website builder should be useful to both the new and experienced. Also, a good website builder should create a page that looks professional (which is the goal of any business website). Speaking of a professional website, you can try one here: http://www.rapidweb.com/online-website-builder.php.
If you have more experience, a website builder can be starting point of your site. After selecting the themes of the website, you are able to further design the site using html and css. Try the demo and see for yourself.