What do we know about societies that leave behind written records?

From the fact that records were written we know that members of those societies could both read and write, we also know that they deemed it important to leave a record for future generations. 
From the contents of those records, we know of events that occurred in that society however we must take care with any records that are based largely on opinion since they are likely to be biased. 

The first one is russia because in russia they were on the rough times and they never had a way to get out of