Resources
Gentle introduction to the math of INLA
There’s a blog at Precision Analytics that does a good job of describing the math of INLA without getting bogged down in details and derivations: https://www.precision-analytics.ca/articles/a-gentle-inla-tutorial/
Examples from Statistical Rethinking
Julian Faraway has re-worked many of the examples from the “Statistical Rethinking” book using INLA: https://julianfaraway.github.io/brinla/
Tutorial
There is a tutorial here that works and does an OK job of explaining itself, but the code is (IMO) poorly written. That makes it a little difficult to really understand the examples. However it has the benefit that the code all works the way the texts says it will!!: https://ourcodingclub.github.io/tutorials/inla/