Documentation is divided into a few categories, such as "Virtualization", "Installation", and "Administrative and User Accounts", which covers the common types of service you'll be managing with your Cloudmin installation. Within each category you'll find a few types of document, such as "FAQ", "Troubleshooting", and specific task guides.
Pages labeled "FAQ" or "Frequently Asked Questions" are intended primarily for common questions new users, or potential users, ask about Cloudmin and the machines it manages. For example, the FAQ for Xen includes a brief, non-technical, description of the Xen virtualization layer and how Cloudmin interacts with it. The FAQs are generally non-technical in nature, and do not generally provide solutions to problems. They are conceptual and broad, merely to describe the way Cloudmin does things.
Pages labeled "Troubleshooting" are intended to help you solve specific problems. If you are receiving an error message from a service or Cloudmin, the troubleshooting section for that particular area may have solutions. Troubleshooting pages are specific and technical, and are intended to help you solve problems.
You can also search just the documentation by opening the search form and using the Advanced Search form to search within content "Only of the type(s)" and choosing "Book page".
The search page, by default, searches all of the content on Virtualmin.com, including forums, issues, and documentation. This may, or may not, be what you want, depending on the questions you have.