Nothing special I guess. Mostly the rust book and reference manual + duckduckgo search which bring up the odd blog post or SO question. But I think it depends

Nothing special I guess. Mostly the rust book and reference manual + duckduckgo search which bring up the odd blog post or SO question. But I think it depends a lot on your previous experience. If you have experience of other languages, particularly c/c++ and some functional style thing like Haskell there isn't that much of a mental barrier IMHO.