I really like comunism history and already red a lot of books about the transition from tsarism to communism, the only thing i never got into is the philosophical conception of communism. I study Russian communism history only in my free time and never attended any course about it so it's too hard fo me to go through all the Capital to understand what communism is about. Is there a book that sums up what communism is and in the specific what Marx mean with communism? If you can also suggest me a book that is traslated in Italian that will be great!
For a short and simple rundown of the tenets of communist ideology in the Marxian tradition I'd recommend reading Marx's "The Communist Manifesto" and also "The Principles of Communism" by Engels. For a bit of a longer introduction and summary of the life and ideas of Marx and the political/philosophical context in which he wrote, I'd recommend "The Revolutionary Ideas of Karl Marx" by Alex Callinicos.
The texts widely seen as "fundamental" reading for Marxism in terms of philosophy would be "The Communist Manifesto" by Engels and Marx and "Das Kapital/Capital: Critique of Political Economy" by Marx. These are certainly both available in Italian, though I'm not aware of specific good translations.
Definitely read "The Communist Manifesto". There's certainly an Italian translation and it's very approachable. "Socialism: Utopian and Scientific" by Engels is also worth a look. When it comes to secondary authors, David Harvey's "A Companion to Marx's Capital" is quite helpful when it comes to making Capital more approachable, though I'm not sure if it's been translated into Italian. Harvey also has some helpful lectures on his website. I also appreciated "An Introduction to Marxist Economic Theory" by Ernest Mandel.
If I can bother a follow up. Whose translation was widely available at the time?