Books
- Writing a Simple Operating System from Scratch by Nick Blundell.
- How to Make a Computer Operating System by Samy Pessé
- Operating Systems: Three Easy Pieces by Remzi H. Arpaci-Dusseau and Andrea C. Arpaci-Dusseau
- The little book about OS development
(Erik Helin, Adam Renberg)
- (HN discussion has more references).