So far, I've read a few from Tucson and a few Tombstone. Some of it is familiar to what we see in today's media: advertisements, local events, political jargon about candidates. But there are a few differences. They write about Native Americans in a very hostile way (using the word "savages" more than a few times). huge mysteries such as unexplained murders are casually mentioned in a few sentences at the bottom of a page. There's a lot of information for gold miners.
Ultimately, they mix opinion and fact way more than journalists should... although maybe that actually is similar to today's media.