Linux Kernel Development (Developer's Library)
The Linux Programming Interface: A Linux and UNIX System Programming Handbook
Understanding the Linux Kernel: From I/O Ports to Process Management
Linux Device Drivers: Where the Kernel Meets the Hardware
C Programming Language
Windows Internals, Part 1: System architecture, processes, threads, memory management, and more
Understanding Linux Network Internals: Guided Tour to Networking on Linux
Designing Data-Intensive Applications: The Big Ideas Behind Reliable, Scalable, and Maintainable Systems
21st Century C: C Tips from the New School