as far as I can tell, none really good ones exist yet...

the documentation is still scattered. The official website [1] is a good starting point. and I wish I'd seen this [2] earlier (I hope this gets incoporated into the official resources)

[1] https://ziglang.org/learn/

[2] https://www.lagerdata.com/articles/an-intro-to-zigs-integer-...

This is probably the most comprehensive resource: https://ziglang.org/documentation/master/

Start with Ziglings: https://github.com/ratfactor/ziglings and then after working through all the exercises read chapter 2 of ziglearn.org.

https://ziglearn.org is a nice way to start!

The language has not reached 1.0 yet, it would be silly to write a book at this stage.

You can find documentation on the language website, also there is an active community and you can ask questions direction on Discord.