Some generic things I did before my interviews:
I did all of these because I've already worked for one corporation and swore never to make the same mistake again. I love smaller and friendlier environments.
Then,
I review the job ad once again. A single job title can represent two different job roles in two different companies. I outline the areas I expect to help out and make sure I'm up to date with whatever is going on in that field.
Also:
I prepare a list of questions about the company and the team.
It's all about the right fit. I may have the skills the company needs, but if I don't like the team or the hiring manager, that's it, I'm gone.
I could never do my job right if it weren't for the support of my team, so I'm always concerned about working with kind and helpful people. It's best when you and your coworkers are working towards the same goal, and not stressing about who did or didn't do what. Bad culture fit is what causes true damage to a company.