Defining what socialism and capitalism is rather than what the best policies actually are is a bad way to go about it because every nation's political situation and discourse is vastly different. Most self identified socialists in the United States would at least be content with most of the policies within the Nordic Model (ie, literally Bernie Sanders, a self identified socialist who stated Denmark should be a model for policy). Most far left parties in Europe on the other hand would see that as a weak compromise.
I think anyway the most standard definition, based upon ownership the means of production, is rapidly becoming obsolete because real political and economic power doesn't necessarily correlate with that anymore. Personally, the books that influenced me the most was the Logic of Political survival, the author of which also wrote a very entertaining and accessible summary of in The Dictator's Handbook, which approaches the likely outcomes of political and social structures from the perspective of how the leader needs to behave in order to stay in power.
Basically, the more power in centralized in a few hands, the worse things get for the average person, and the more the system requires vicious and corrupt behavior by those in top to even survive and stay in power. Whether that power is concentrated in the form of a CEO who stacked the system so he isn't really accountable to his employees or common shareholders in any way, or a Stalinist Dictatorship, unaccountable power is bad and should always be minimized if you want a just society.