Have you not gone through the principles section in the help file? It is fairly good for showing the basics of DB programing. I am not sure from your post if you are totally new, and don't know how to to the most basic things, or already know a bit and just are not sure of some of the more db specific commands.
I find it hard to find much on physics and online multi player for instance. There are bits here and there, but no real gritty tutorials. I bought dark physics as soon as it was released, but due to never understanding it, haven't used it a lot(bang went my hopes for a driving sim that I foolishly thought I may be able to try. I always wanted to make one since first sitting down to play the original Outrun in the arcades).
http://s6.bitefight.org/c.php?uid=103081