Book: HTML and XHTML Step by Step, by Faithe Wempen (February 2006). Discusses the basics of HTML and XHTML, document structure, formatting text with tags, using lists, using backgrounds, creating hyperlinks and anchors, style sheets, formatting text and paragraphs with style sheets, displaying graphs, creating navigation aids, creating tables, formatting tables, division-based layouts, user forms, using frames for layout, incorporating audio and video, HTML and Microsoft Word and FrontPage, usability and accessibility.
Book: Sams Teach Yourself HTML in 10 Minutes, 4th ed., by Deidre Hayes. Discusses what HTML is, what XHTML is, how HTML and XHTML work, web browsers, required elements, saving and viewing a page, XHTML requirements, paragraphs, text emphasis, headings, special characters, math and science notations, meta tags, what a URL is, hyperlinks, linking, style sheets, defining rules, applying styles, formatting, adding lines, lists, tables, graphs, mapping images, frames, forms, sound, video, designing with HTML, active web pages, and web authoring tools. Appendices cover an HTML/XHTML quick reference, a style sheet quick reference and special characters.
Book: Head First HTML with CSS & XHTML, by Eric Freeman and Elizabeth Freeman. Discusses getting to know HTML, hypertext, web page construction, getting connected, adding images to web pages, HTML standards, HTML compliance, moving to XHTML, getting started with CSS, styling with fonts and colors, elements, advanced web construction, layout and positioning, tables, lists, XHTML forms, selectors, frames, multimedia, Flash, tools, client- and server-side scripting, search engines, mobile devices and blogs.
Book: HTML and XHTML Pocket Reference, 3rd ed.
, by Jennifer Niederst Robbins (May 2006). Discusses the fundamentals of HTML and XHTML, how XHTML differs from HTML, versions of (X)HTML, minimal document structure, DOCTYPES for available DTDs, common attributes and elements, (X)HTML elements, character entities (such as the ASCII character set, mathematical operators), and specifying color.