I have been reading Kropotkin's Mutual Aid, as well as The State:its Historic Role, and find his descriptions of the medieval commune/free city very interesting. He focuses (obviously) mainly on the mutual aid institutions present, and perhaps is idealistic or overly focused on the good. An example:
"In short there is a massive and varied documentation to show that mankind has not known, either before or since, a period of relative well-being assured to everybody as existed in in the cities of the Middle Ages. The present poverty, insecurity, and physical exploitation of labour were then unknown."
"With these elements - liberty, organization from the simple to the complex, production and exchange by the Trades (guilds), foreign trade handled by the whole city and not by individuals, and the purchase of provisions by the city for resale to the citizens at cost price - with such elements, the towns of the Middle Ages for the first two centuries of their free existences became centers of well-being for all the inhabitants, centers of wealth and culture, such as we have not seen since."
Are his depictions of commune life accurate?
What works is it worth reading to learn more about life in the communes?
Ok, there is a lot to unpack here. First of all, it needs to be stated that so many of the great Marxist theoreticians have completely misguided views on the Middle Ages (especially Marx :/).
Now, there were certainly many mutual aid societies in medieval Italian cities (which I know best). If you want reading material, I would check out, Liberty, Charity, Fraternity: Lay Religious Confraternities at Bergamo in the Age of the Commune by Lester Little. In addition to confraternities, the mendicant orders of the 13th century further ministered to the poor.
Despite the existence of these institutions, it would be foolish to assume that there was not exploitation of labor. The guild structure could be highly exploitative. Look at the Ciompi revolt, it was a rebellion of the wool carders and similar low-skill laborers who were completely marginalized by the more powerful elements of society.