Different pre-departure orientations in different countries/consulates will probably cover a variety of topics. As far as what "The JET Programme" offers, the standard orientation is Tokyo Orientation. You can access the handouts from previous years at http://jetprogramme.org/e/current/confe ... o_ori.html
. Note that the topics and workshops change from year to year, though, so if you do get accepted to the Programme, you might end up with a different set of workshops to choose from.
Prefectural Orientations will often cover work-related topics, but the prefectures are responsible for planning them, so content varies from place to place. But as far as learning how to teach, it will be a lot of learn-as-you-go, although other resources such as National AJET (see this awesome page in particular: http://ajet.net/education-professional-development/
) and JALT (http://jalt.org/
) are pretty useful--it's just that you'll need to make use of these with your own initiative.