What type of info is more useful?

I think that I would prefer to know things that I shouldn't do. Because acting in a wrong way may get one into real trouble or even dangerous situation. "Things to do" however, are more helpful if you are already in such situation. It's definitely better to avoid such situations, so I would surely prefer the "things not to do". Some kind of saying I heard was something like that: "To be warned is to be armed"

I think what not to do is more helpful, because those are the things that get you in trouble most of the times, and if you don't do what you shouldn't do then you would have no problems. You can then try out the product or the idea in question safely. Especially when it comes to programming if you don't have proper data on what not to do, it might cost you a lot of effort, time and money.