There are several pages up on how the actual Dobro and National steel guitars are set up.
All the videos by Jim Farris are incredibly helpful. He showed me how to make a good scarf join. He also builds a cake pan resonator. Here is a link to all his videos. Sorry, it is on veoh, and you have to watch ads an see suggestions for other "related" videos to watch. (But I am sure I don't understand how fitting a bra properly has anything to do with cbgs . . .)