I definitively agree. Finding that valuable information that you need for developing extensions has always been difficult and cumbersome.
Also there should be a section in the docs concerning extensions. A general description of extension-development, a few HOW-TO's to get you going, the API (or at least a link to it), links to helpfull articles and so on.
@André: there is stuff in the tracker so old that it will soon be part of the UNESCO World Heritage List ( http://whc.unesco.org/ ) :-)