If you have a wordpress site then it is very simple. You just need to get the following plugin :

WordPress › Google XML Sitemaps « WordPress Plugins

Thank you for the tip - However I am referring to non-wordpress sites.

Create your Google Sitemap Online - XML Sitemaps Generator

Then use this one :

Create your Google Sitemap Online - XML Sitemaps Generator

Yes, pretty much. There is a good article and video by Matt Cutts here:

HTML Sitemap Explained - XML Sitemaps Generator

The site also has a free generator that will generate an html site map from your root URL:

Create your Google Sitemap Online - XML Sitemaps Generator


Mahlon

EDIT: LOL Look at all the answers typed at the same time

You may want to read this article first discussing all the various sitemap types:
Sitemap Comparison of Text, HTML, ROR, RSS and XML Sitemaps

(contains both explanations and code examples of all sitemap file types)

I like Dagon Design's Sitemap Generator because they create a sitemap that separates your posts by category and your pages. It's more user friendly, but to tell you the truth you really don't need to create a sitemap for humans they're really designed to make it easier for the search engines to navigate your site.

hello friend, creating a XML sitemap and submiting it to GWT tool help for proper webpage indexing in Google. Also, make sure to check http status codes of URLs and validate the sitemap. All top search engines like Google, Bing, Baidu, http://www.oko69.com ..... are pretty sensitive for sitemaps.

additionally, using a XML and HTML sites together can be more fruitful.
thanks

There are many xml sitemap plugin on Wordpress, what you need to do is to search there, you can use one according to your preference.