To add onto this: Parenti is a great start, but I think one shouldn’t just throw books at people. Instead, take what the book says, boil it down, and use it as your argument. Then reference the book as a resource to learn more. So for example, if you want to explain that capitalists will always favor facism over socialism say something along the lines of:

“Well, the rise of both Mussolini and Hitler was actually made possible by capitalists who looked favorably upon the harsh anti-union, and more broadly anti-socialist, stances Mussolini and Hitler took. For example, German Industrialists paid for a lot of the trucks and loudspeakers Hitler used to recruit voters. This pattern can be seen repeated throughout history where fascist dictators were often installed by imperialist/capitalist countries to prevent the nationalization of resources so they could continue exploiting them. If you want to learn more about this I’d recommend Michael Parentis “Blackshirts and Reds” It’s a great introduction to this and reads quite easily in my opinion. I can also provide you with a PDF if you’re interested”