This is a topic I'm very interested in. I have a few links (no books sorry), and would be keen to talk to you if you're interested (email in bio). I have had fantastic success with negotiating benefits and extra pay, just the other week I received 4 weeks paid paternity leave up front on top of an already generous salary offer. It is a skill worth having

Steli Efti negotiation course (requires email registration) : https://courses.close.io/ Our very own patio11 : https://www.kalzumeus.com/2012/01/23/salary-negotiation/ Valerie Aurora : http://valerieaurora.org/howto_salary/