Main references
(O'Reilly Textbook) HTML, XHTML, and CSS Bible, 5th Edition, Wiley Publishing by Steven Schafer | Companion Site (though not much there beyond a Code Download)
W3Schools tutorials on HTML and CSS (and possibly others)
Note: Visit Accessing O'Reilly online texts for login guidance to O'Reilly resources
Other resources
A Primer on XML (Extensible Markup Language)
Core Microsoft Office Students enrolled at Augusta University get free access to Office 365 which works on a Mac or PC and includes full versions of Microsoft Excel, Word, PowerPoint, Publisher, OneNote, Skype for Business, InfoPath, and OneDrive (and, for PC's but not MAC's, Microsoft Access). Other tools are also available to students. Visit Augusta University Software for installation notes.