I've been dipping my toe into the waters of writing historic fiction. One of the biggest challenges has been recreating a given time in both technology and attitudes. Even for years I lived through (one story would be set in 1985,) it's hard to remember what did or didn't exist and how people thought and behaved.
It's relatively easy to research the major world events for a year, but how would you go about looking for the details of everyday life? There are a few good books on specific time periods, but what sources do actual historians use?
That greatly depends on what time period you are looking for. My area of specialty is ancient history, specifically in the Ancient Near East. We use a lot of evidence from archaeological excavation to find out what life was like two to four thousand years ago. When we analyze artifacts, we see the technology that is available, we see how things were used based on where they were found and what things they were found with. Some things come from writing, if you have written things available.
If you are more interested in a time a little closer to the present (i.e. within the last few hundred years), there are a lot more written documents that you can use. I am not as familiar with these, since I do not study these periods, but you should be able to find letters between people, or even newspapers, or pretty much anything written during the time you wish to write about, and that will give you important information about what daily life was like.
If you let us know what your time periods are that you want to find information about, let us know and we can try to be more specific.