As per as I know, you can follow two text books. 

1. Linux Kernel Development by Robert Love, 3rd edition. 

2. Linux Device Drivers by Alessandro Rubini, Jonathan Corbet, Greh Kroah-Hartman. 3rd edition.

At the same time, you can practice the exercises given in the text books - practice makes a man perfect. The other thing is "Make your hands dirty by digging the kernel code whenever you have a doubt".

Regards,

Srinivas