As far as the actual interview goes, they do not ask you traditional interview questions, like 'why should we hire you?', 'what are your weaknesses?', 'why do you want to work here?' and so on. They ask for you to give examples of times that you solved problems, worked as a team, maintained quality control under a deadline, followed rules that you didn't like, etc. There are about 10-12 questions like this, and it is challenging to come up with situations to apply to such specific questions.
It's a tough interview for what seem like basic jobs. They are far more interested in your work ethic, ability to work under pressure, fit into their corporate culture and maintain quality control.