Historical newspapers are especially useful for examining events in context of when they happened. They can often be used as primary research, depending on your discipline, but always provide the perspective as events as things were happening when they were happening.
When you search in historical newspapers, sometimes it's a good idea to search for a specific person or event. Often you can also limit your results by date too. These are easy ways to help limit your results and hopefully find resources that will be useful to your needs. You can also use keyword searching too if you want your results to be broader or maybe cover a greater expanse of time.
Some collections of newspapers are organized by themes or topics. These can include things like gender, race, war, etc. These newspapers may include broad geographic regions, but provide diverse perspectives on a specific topic. When searching in them, you will want to be mindful of how you are searching - what keywords you are using and what limiters (like date) you are placing in your search.