Dedication
With thanks to the resources and people that taught me:
- The volatile, incredibly productive folks at the Daily Japanese Thread
- Alexander Vovin (japanese linguistics papers)
- Thomas Pellard (japanese linguistics papers)
- Sven Osterkamp (japanese linguistics papers)
- A Reference Grammar of Japanese (Martin)
- A History of the Japanese Language (Frellesvig)
- A Dictionary of Japanese Grammar series
- A Dictionary of Japanese Particles (Kawashima)
- Visualizing Japanese Grammar series
- Yan and the Japanese People (Let's Learn Japanese 1&2)
- Steve at Nihongonomori
- Tae Kim
- Imabi
- Ixrec
- kWhazit
- Reading
Notes about some of the above:
Vovin was once a proponent of Altaic, which is crackpottery disguised as linguistics. Vovin is a fantastic academic and his turnaround and conversion to "real linguistics" was basically as epic as anything in academic linguistics gets, but keep in mind that a lot of his old work is based on faulty premises.
A Reference Grammar of Japanese contains a lot of useful references, but all jargon and categories in it should be taken with a grain of salt. It was compiled at a time when the specific domains of linguistics necessary to compile a reference grammar were restructuring their categorizations.
A History of the Japanese Language is highly incomplete, even beyond the fact that history is so hard, there's a lot of known information it doesn't cover.
A Dictionary of Japanese Grammar has several translation errors in its examples and doesn't always subscribe to real linguistics terms, but its notes are good.
Yan and the Japanese People is nearly impossible to acquire legally today.
Steve's videos are the only Nihongonomori videos worth watching.
Tae Kim isn't a linguist, even though he's right that most textbooks are awful. Many of his explanations try so hard to avoid being technical that they end up confusing or misleading, like his "focus particle" explanation, and the way he deals with grammatical aspect (てくる and ていく in particular).
Imabi's guide was originally written in dense "academic" english and used to be unnecessarily hard to read. However, as of mid 2017, the beginner's material is finally being rewritten, so there's no reason to avoid it anymore if you need more informative explanations. The intermediate and advanced parts are still littered with hard writing, but they contain information that's very hard to find in other free resources.