There are a few mailing lists to subscribe to so you can take part in how the LDP works. First is <email@example.com>, which is the main discussion group of the LDP. To subscribe, send a message with the subject reading "subscribe" to <firstname.lastname@example.org>. To unsubscribe, send an e-mail with the subject of "unsubscribe" to <email@example.com>.
Another list is the <firstname.lastname@example.org> list, which is for markup or other questions about DocBook itself. If you run into trouble with a particular markup tag, you can send your question here for answers. You can subscribe to the DocBook list by sending a "subscribe" message to <email@example.com>.
There is also a mailing list run by OASIS that can also answer DocBook questions. Please see http://docbook.org/mailinglist/index.html for more information about the mailing lists. The LDP prefers our own list, but only because the LDP list focuses more on tag usage than other questions such as formatting.