A guide to the Kernel Development Process — The Linux Kernel documentation

Working with the development community
Internal API manuals
Development tools and processes
User-oriented documentation
Firmware-related documentation
Architecture-specific documentation
The purpose of this document is to help developers (and their managers) work with the development community with a minimum of frustration. It is an attempt to document how this community works in a way which is accessible to those who are not intimately familiar with Linux kernel development (or, indeed, free software development in general). While there is some technical material here, this is very much a process-oriented discussion which does not require a deep knowledge of kernel programming to understand.