How important is having a sitemap and how do I create one?
 

People say that it is very important to create a sitemap. I don't know how to make one. When I used Wordpress for my sites this was very easy and I've done it with a plugin. But how would I make one with just a html site for example?

There are some of the tools to generate the sitemap. Sitemap is important for a website, easy to navigate to other pages.