Joseki resources:
- Waltheri
- OJE – OGS Joseki Explorer
- Josekipedia
- EidoGo / Kogo’s
- Sensei’s Library
- Watching pro games on Tygem and Fox
- This list and this system for navigating 3-3 invasions
- Pros Yeonwoo, Young Sun Yoon and their collaboration AwesomeBaduk
- Pro Michael Redmond
- Nick Sibicky. According to this list, Nick has made at least twelve videos on joseki and at least six on invasions.
I was going to mention Joseki Farm, but apparently it’s died.
For general resources, see everything classified as Teaching in the Thread Guide – that includes TonyBe’s 19x19 for Beginners and three series by Mark5000.
Tsumego:
- OGS Puzzles
- Tsumego Hero
- Tasuki
- Go Problems
- Sensei’s Library beginner exercises and kyu exercises
- 101Weiqi
It’s lightly recommended to begin with Cho Chikun’s Elementary Encyclopedia of Life and Death (aka the Elementary Chomego), which you can find on OGS Puzzles and Tasuki.
For free reviews, ever since the Go Teaching Ladder died, GoKibitz has been the only real option.
Watching pro games:
- the pro game reviews on Youtube list
- BadukTV
A couple more helpful lists:
For Discord servers, I recommend BenKyo’s, Clossius’ and the Open Study Room. Perhaps BeginnerGo as well. There’s a document called the Discord Discovery Guide which lists more (I don’t have it, I think it was made by Gooplet).
As goes forums, you’ve already found this one. There’s also Life in 19x19 and at least two subreddits (r/baduk and r/proweiqi).
Especial shout to Redmond’s beginner playlist and Yeonwoo’s explanation of the early 3-3. Oh, now I see that Redmond’s made a 3-3 video as well.
Keeping up with professional events:
- Life in 19x19 Professionals board
- Go Ratings and a browser script to enhance it
- Spotlight on the top professional male and female players of each country
Free journals:
- American Go Association E-Journal
- British Go Journal
- Ranka (International Go Federation) (+ old paper editions)
For paid teaching, the only person I recommend to begin with is BenKyo, whose cheapest rate is at $15 / 45m + perks. (Disclaimer: I mod for Ben.) Check out the prices of other teachers and schools for comparison.