Online, there's the XML Specification and ancillary documentation available from the W3C; Robin Cover's SGML/XML Web pages with an extensive list of online reference material and links to software; and a summary and condensed FAQ from Tim Bray.
The items listed below are the ones I have been told about. Please mail me if you come across others.
- An annual XML Conference is run by the Graphic Communications Association. XML 2001 is in Orlando, Florida, on December 9--14. See the GCA's Web site for details.
- The Extreme Markup Languages 2001 conference takes place on 12--17 August at Le Centre Sheraton, Montréal, Canada.
- The annual XML Summer School takes place in Oxford on 20-25 July 2001.
There are many other XML events around the world: most of them announced on the mailing lists and newsgroups.
There are lists of books, articles, and software for XML in Robin Cover's SGML and XML Web pages. That site should always be your first port of call: please look there first before using the form in this FAQ to ask about software or documentation.