Just found on the ejabberd mailing list Anders Conbere’s blog, with quite a lot of information to get you started, and code for the http server, write a bot.
[U] And Jack Moffit in the comment directed me to his weblog. Very good read about ejabberd deployment and administration.
Both of these live well in my NetNewsWire subscriptions.
Other locations
The Process One wiki is also a location to bookmark. All the standard hooks are listed.
Last but not least, the source code ! The simple features of erlang make it quite easy to navigate through the source code.
Modules you’ll use on a frequent basis are jlib, ejabberdrouter, xml and xmlstream along with mnesia and lists.
jlib : for manipulating JIDs, iq stanzas
ejabberd_router : send your stanzas elsewhere
xml_stream and xml : for parsing xml into the internal tuple representation or the other way round.