Official tutorials for Microsoft Word 2007 and later are available on Microsoft Office's official support page. Microsoft no longer offers official support for any of the previous versions, but a large part of the most recent tutorials apply to earlier versions as well.
To find the official tutorials, access Office.live.com and click Support. At the next page, in the Top Solutions section, click Office Training, Videos and Tutorials. Find the section for your version of Office and click the Word icon in that section. The Microsoft Word 2013 section has the widest and most detailed selection of courses and tutorials as of 2015. Courses are divided according to the user's level of proficiency with the software.
The Beginner section teaches basic functions such as creating a document, setting a custom and a default margin, adjusting line spacing, using the spell check function, tracking changes and working with word counts. The Intermediate section explains how to create labels, add footnotes, set mirror margins, change the orientation of the document, use quick styles and work with watermarks. Lastly, the Advanced section goes through the various advanced settings in mail merge and explains how to add collapsible headings and an advanced table of contents.