I’m just getting back into Go. The last time I played was probably 15-20 years ago and I was only a beginner then.
I’m looking for good resources for basic patterns, joseki and an introduction to territorial control so I can refresh myself before getting into basic games.
Is there a good list of references somewhere or can someone recommend books? (I am already looking into Ishigure Ikuro - Elementary_Go_Series but other resources would be appreciated.)
also this for a compiled list of various things:
welcome back 
to me, this sounds like haengma. a good book that discusses it for beginners is Janice Kim’s Way of Moving Horse
I’m 8-9k and still just look things up in OGS dictionary right here. I think you can lean some simple joseki from here, 6 moves or so long, and then study after your games to see what comes up. better to spend time on other things than joseki as a beginner
tbh, although the game is about controlling territory, I don’t know of good beginner resources focusing on this. it sounds like a more advanced topic, but maybe you want to learn about building territorial frameworks, some times we call that a moyo (模様) so try googling for it
instead, I’d look for things talking about groups, and thinking about groups being weak or strong. so basic life and death, like puzzles: Play Go at online-go.com! | OGS
I think another good book aside from Janice Kim, is Richard Bozulich’s The Second Book of Go. it gives you a little of everything in a small package, but quality stuff
for non-book resources, I have recommended Clossius’s beginner lecture series to many friends. it’s what got me over the hurdle of playing 19x19, and I think he covers a lot of ground in a digestible way for a beginner who has only played small boards a little
remember, play lots of games too, not just reading. it can be scary but you’ll have more fun. good luck!
Joseki resources:
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:
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:
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:
Free journals:
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.
By the way, I just checked the Go4Go forum that’s linked on the OGS Resources page.
Sad to say, it looks like it’s been dead since before Covid and is now overrun with pharmaceutical spam.
The list of "other resources " that you can access with the OGS menu is surely another good place to consider (including more choices for a teacher as @bugcat suggestion).
A word on the AI revolution
Because of what AI brought to us (around 2017), mostly new perpectives on the beginning of a game, you need to have some distance with anything on fuseki (opening patterns and theory) and joseki published before AI and that is a lot of resources!
This includes for example the “in the beginning” book of Ishigure you mentioned in the OP (Sadly as i loved that book)
See this topic for more on this
Oh thanks