The ingame guides are an okay starting point as far as learning what affects what and so on. There is a little first playthrough guide in there which handholds you through the first few weeks. While there's other ways to play, following that can at least set you up for the future and get you familiar with how some stuff works.
Simple way to 'gently' break a slave:>Poor living conditions>Make her wear ballgag and uncomfortable latex/shibari/straps>No speaking freely, no relationships with other slaves>Punish with chastity, reward with orgasm>Only allow sex with you>Rest, fucktoy duty or classes if she doesnt have education
Hormones and curatives can also help, for a price.
Other stuff can be adjusted according to their drawbacks - restricive diet if they're too fat, corseting for a large waist etc. Personal attention on them is optional and can help even more to fix flaws.
Give it a few weeks under those rules and they should hit Accepting, at which point they can be sold for a profit or built towards whatever job. Shouldn't get stuff like mindbreak or addictions, either.