Start with high-confidence rap & hip hop books, then narrow by subgenre or adjacent topics.
E.a.r.l.
DMX, Smokey D. Fontaine
Sweat the Technique
Rakim
Can't Stop Won't Stop
Jeff Chang, D.J. Kool Herc
Kanye West Owes Me $300
Jensen Karp
Beastie Boys Book
Michael Diamond, Adam Horovitz
Remember the Times
Teddy Riley, Jake Brown
Fashion Killa
Sowmya Krishnamurthy