when i was in school i fed obsessions with the library cataloge.
i was lucky because i had access to a world class library. i would normally start with a wikipedia entry, use the footnotes to get started with basic sources--figuring out who the prominent voices/authorities are on the topic is the first thread you want to pull--if you read them and find them interesting, try figuring out who they were reading (again, using footnotes/references).

i think it's basically what happened to me with bitcoin, except that the "references" are a little more convoluted, hence the idea that it is a "rabbit hole."