The Rust Programming Language
by Rust Project
The official book — the best starting point for learning Rust from scratch.
Discovery: Microcontroller Rust
by Rust Embedded WG
Hands-on embedded Rust book — blink LEDs, set up a probe, write no_std code.
Related resources
Rust by Example
by Rust Project
Learn Rust through annotated examples covering core concepts and the standard library.
Rustlings
by Rust Project
Small exercises to get you used to reading and writing Rust code.