Related: https://nostarch.com/building-a-debugger is close to publication (currently in Early Access) and covers building a debugger for x64.
Anyways I can recommend it even though I am not finished with it yet.
I work on CNCF Pixie, which uses DWARF for eBPF uprobes and dynamic instrumentation. While I understood how our project uses DWARF, the book made many details much clearer for me.