The minimum requirements to publish a website would be a domain name and a hosting account. Once your site is created either with a template based program like Website Builder or with 3rd party software. The next step is to submit and optimize for the search engines if you want traffic to your site. There are many ways to do this but one of the best ways to start out and get initial submission and optimization is to use an optimization program such as Search Engine Visibility. I have found this program to be a valuable resource on the search engines as well as automating the submission process and providing optimization tips and keyword and meta tag suggestions.