You can start here.
http://darkbasicpro.thegamecreators.com/?m=forum_view&t=25076&b=7
First, you must learn the language. Read the manual, few ppl seem to do that lately. If you read through the manual, you'll more than likely be helping other newbies in no time. Read the description of the commands that make sense and sound simple, then try to write a program that uses that command in a creative way. Play around. Learned how to print "hello world" on the screen already? Then get creative. Make the letters bounce around the screen now. By doing this, it'll help you to solve problems involoving real world applications in the future. Reverse engineer. Find a simple program already written, then rip it apart to see what does what. Most importantly, try to understand why something works. That's what helps you to apply that knowledge onto other tasks. And when you're stumped, ask us at Apollo(this website).
"eureka" - Archimedes