That's the only Dark Basic book I know of on programming.
The rest to learn is pretty much by experiment and asking others.
Here are a couple essential sites under this link, for more game programming tutorials.
http://www.darkbasic.com/create.php?f=sites_index.php
DB toolz-
http://www.dbtoolz.50megs.com/
Dark Forge(currently under constuction, but still has some stuff)
http://www.darkforge.co.uk/files/
DB planet(recommended) not very full in tutorials currently, but it has 10 links to more dark basic webpages on the right hand side.
http://www.darkbasicplanet.com/
I hope this post helps you find a couple tutorials, or new tips on designing,programming, and becoming more advanced overall in darkbasic.
(Current)-Game entering concept art stages-
(progress)-Should have demo in 6 months latest-
(misc.)-Started modeling buildings and other objects-