Oh my. Don't let me off my hip hop leash or I will BORE you forever more lol. What era and region are you most interested in? If it's West Coast rise of gangsta rap then I highly recommend To Live and Defy in LA by Felicia Angeja Viator. It roots the rise of gangsta rap firmly in the crack epidemic and horrific police oppression of suffering Black LA communities in the 80s, and explains how gangsta rap and NWA rose up as a way to protest against all that and take back the power. It covers the FBI's attempts to silence NWA for callling out police oppression too. A very robust sociological study using primary oral sources from people who were there.
If the East-West Coast feud and the assassinations of Biggie and Pac are more your thing, then I would say there's so many vested interests and obfuscations that it's very hard to find good, neutralish reliable documentation. But I would recommend the book Welcome to Death Row by S Leigh Savidge and the accompanying documentary which you can find (in bits and pieces but you should be able to string em all together) on YouTube.
For the assassinations of Biggie and Pac, NO ONE is neutral and the book you decide to read is kinda governed by who you think did it lol. I would go for Murder Rap by Greg Kading, who was a LAPD detective brought in to re-open the Biggie case and ended up accidentally solving Pac's too. That book is the basis for the recent Netflix series, and is the most sensible/least nutty take on the whole thing, imho. Kading is the one I think gets close enough to what really happened. He also has a couple of excellent interviews on the hip hop YouTube channel, djvlad.
If you're interested in modern day gangsta rap and the tragi, constant but very interesting beefs, wars and killings, then may I recommend the YouTuber Trap Lore Ross. Despite being white and British he is respected in the streets of Chicago, NY and Jacksonville for making brilliantly sourced and meticulously researched videos on the Chicago, Bronx and Jacksonville drill scenes. But be warned a lot of the individuals he covers are extremely violent and some I would say genuinely demonic individuals so you'll need a strong stomach.
If you need anything else just let me know, I could honestly go on about this for hours but trying to keep my ND-driven hip hop nerdiness in check here