First, a short personal note to make you understand why this is important to me. To make a long story short, the son of a friend has some atypical form of autism and language troubles. And that kid matters a lot to me, so I want to become stronger in helping him, to be able to better interact with him and help him overcome his troubles.
But I don't know much about psychology. I'm a computer scientist, with a general background of maths and physics. I'm kind of a nerd, social skills aren't my strength. I did read some of the basic books advised on Less Wrong, like Cialdini, Wright or Wiseman, but those just give me a very small background on which to build.
And psychology in general, autism/language troubles in particular, are fields in which there is a lot of pseudo-science. I'm very sceptical of Freud and psychoanalysis, for example, which I consider (but maybe I am wrong?) to be more like alchemy than like chemistry. There are a lot of mysticism and sect-like gurus related to autism, too.
So I'm bit unsure on how from my position of having a general scientific and rationality background I can dive into a completely unrelated field. Research papers are probably above my current level in psychology, so I think books (textbooks or popular science) are the way to go. But how to find which books on the hundreds that were written on the topic I should buy and read? Books that are evidence-based science, not pseudo-science, I mean. What is a general method to select which books to start in a field you don't really know? I would welcome any advise from the community.
Disclaimer: this is a personal "call for help", but since I think the answers/advices may matter outside my own personal case, I hope you don't mind.
When bridging an inferential distance, see where you are now, and then see where the experts are. That should help uncover the ignorance of your ignorance and make it possible for you to move towards the experts in knowledge-space. If you don't know where the experts are in knowledge-space, then you can easily stumble along in the dark until you end up at bullshit.
The next course of action is to actually move towards the experts in knowledge-space. Textbooks, expert blogs, wikipedia, classes, and so on are all viable methods for that.
But besides understanding the area well, I think you also want to understand or mentally model autists. In which case, you should become familiar with actual autists (through e.g. documentaries, books, and personal communication).