I got started with http://www.ontopia.net/topicmaps/materials/tao.html.

Ontopia is a commercial company, but its founders are amongst the authors of the
spec:
http://www.ontopia.net/topicmaps/learn_more.html
In particular, I found http://www.ontopia.net/topicmaps/materials/tm-vs-thesauri.html useful in placing
topic map in relation to thesaurus, ontologies, etc. As far as I can tell, altmc falls under the definition of a glossary.

http://www.topicmap.com/topicmap/tools.html has a good list of tools, APIs, etc.

Ontology-driven Topic maps:
http://www.idealliance.org/europe/04/call/xmlpapers/03-03-03.91/.03-03-03.html

XML Topic Map Specification: http://www.topicmaps.org/xtm/1.0/

One problem I found with XTM is the dearth of authoring tools. Its terrible! I
designed my own text format initially, then found  AsTMa=
(http://astma.it.bond.edu.au/authoring.xsp) which turned out so similar to what
I came up with, I abandoned my format and used it instead.