XHTML Tips
- A collection of help, guidance and tips to assist with web authoring.
- http://www.xhtmltips.co.uk/

Joe Burns: XHTML
- Short page introducing the relationships between XHTML and HTML.
- http://www.htmlgoodies.com/beyond/xml/article.php/3473521

HTML | XHTML articles and tutorials: A List Apart
- A List Apart has many useful articles showing what cane be done with XHTML. Contains step-by-step instructions and tutorials.
- http://alistapart.com/topics/html/

Computer Torture
- Lists of brief guidelines for XHTML and for XHTML-Basic. [Author and qualifications are not identified.]
- http://www.computertorture.com/xhtml/

Simon Jessey: Learning XHTML
- 5 parts including: page structure; lists; hyperlinks and text formatting; tables; and forms. Suitable for beginners, without prior knowledge of HTML.
- http://jessey.net/simon/xhtml_tutorial/

Gowansnet: XHTML Tutorial
- 3 parts: introduction; tags; attributes. The introduction includes the main changes from HTML, the doctype, and document formation.
- http://www.freewebmasterhelp.com/tutorials/xhtml/

Web Developer's Virtual Library (WDVL): Introduction to XHTML
- 5 parts: introduction; XML and XHTML; document type definitions; differences from HTML; and document structure.
- http://www.wdvl.com/Authoring/Languages/XML/XHTML/

World Wide Web Consortium (w3c): XHTML Modularization
- 7 sections: introduction; terminology; module construction; DTD construction; module examples; mark-up language examples; usage examples.
- http://www.w3.org/MarkUp/Guide/xhtml-m12n-tutorial/

XHTML Explained
- Tutorial explaining what XHTML is, describing its benefits, and providing some guidelines for coding.
- http://www.yourhtmlsource.com/accessibility/xhtmlexplained.html

Onaicul: XHTML Design Guide
- 5 parts: introduction (including an historical perspective on hypertext); modularity; document specs; code guidelines; design guidelines; appendices with resources. Each part contains subsections.
- http://www.onaicul.com/xdg.html