Look up the company here on Glassdoor--the reviews, the interviews, the overview, etc. Google them too. When you get the In-Person Interviews, look up the Managers on LinkedIn, Facebook, Instagram--wherever. Look the company up on Facebook and Instagram and LinkedIn. Get a good feeling for the culture because it is a huge deal to them. Also be familiar with what they do, obviously, so they know you're aware of what the job is.