Go for the samples. First make sure you know how to compile things. The secret to learning orbiter stuff is to just do it. A lot of people will recommend C++ books to you. That is all fine, but C++ is not a language you can learn in a day. So if you want to go through that route, you'll be writing useless, and boring stuff for a long time. Whereas you can use Orbiter as a learning tool for C++. Just make sure you are persistent, try to figure things out for yourself. Google stuff, etc. Modify the samples, and make something useful.