Learn Linux File System and Device Drivers

I am to start working on two project on Linux Device Drivers and other on File System.
So I got the book "Understanding Linux Kernel" by Daniel and Marco.
But I am confused as how to proce
Will anybody pls let me know how to go to about studying the chapter in this book? I mean the order in which the chapters need to be covered to get a proper understanding of the device drivers and file systems.
Pls let me know some good book/articles on writing real life linux device drivers basically for GPIO, I2C, SPI and File systems.

Try reading it start to finish, and asking more specific questions if you have difficulty with it.