"I giornali sono degli uomini."
I translated as "The newspapers belong to the men." and it was wrong. I think it sounds a lot more natural than "The newspapers are of the men"
The sentence makes more sense when you remember that possession in Italian is "di". So, taking the verb out of this sentence, you can have the phrase "i giornali degli uomini" "the men's newspapers"; the sentence as it is, then, can be translated as "The newspapers are the men's".
This would be used to answer a question about who the newspapers belong to, so you can't say "the men's newspapers". I think saying "the newspapers belong to the men" should be more acceptable.