Do you have DBC (classic) or DBP(pro)?
Classic comes with huge help files and brilliant examples. It's worth looking at them all and changing/adding/removing code to see what it does.
Alot of the commands are pretty self-explanatory even if you don't know how to use them. It could be worth just reading through all the commands to get a feel for it, then writing simple programs using the help files. As you get better, you'll find faster ways of doing things. I know when I've made a small program, I've written something then realised I could have used a function and saved myself several hundred lines.
Read the forums and look at the codebase too. Tips come up all the time. There are also tutorials in the newsletters which even if you havn't subscribed to you can view on this site.
The hard part isn't learning the language, but keeping your code concise, easy to understand and efficient. At least, that's what I find hard...
Start small though. If your eventual aim is to make an uber game, just make your learning examples relevant to that game. This prevents boredom and that feeling that you're not achieving anything) Save the actual game for later though.
Good luck
[EDIT]
Forgot to mention. If you're using classic, there are a couple of tutorials on this site. The binary moon tutorials are nice. If you're on Pro, take a look anyway. Limit rush is really addicting.
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