Although I don't have any sources, I dispute your assumption that racism and slavery are necessarily related. Both institutions have and can exist without the other. That does not discredit the role each has played in the development of the other.
I think a better question to ask would be "How did racism and slavery develop within ___________ time period/location?" Also note that different regions institutionalized racism and slavery differently, which would impact any better answers.
Some previously asked questions on minorities and the United States might provide more info for you:
I assume you mean slavery specifically in the New World? Since slavery is an incredibly old concept and was occurring in other places alongside the New worlds form.
Depends really on what you mean by slavery and racism. If you mean racism in the sociological sense beyond "xenophobia" and slavery as in chattel slavery, which I assume you mean, slavery caused racism (or, more accurately, the scientific nature of biology at the time combined with the needs of colonial Europeans expanding to the New World created the need for more thorough exploitation of labour)