Good luck! I applied at babies r us a couple of years ago for a part-time second job. The interview was a group interview, I think there were about six of us there all interviewing for two positions, so it was really intimidating for me - we each answered the same question, so we had to make sure to not answer the same as someone who went before us, but also we had to give a better answer, it was very competetive. Not to mention before the interview even started, the store manager started talking about how he dreds coming in to work every morning, but everybody feels that way, right? Heh. Incidently, I didn't get the job, and they didn't even call me to tell me that. It's probably because I left the interview after 2 1/2 hours, because, as I told them in the beginning, I had to get to my other job.
No, I'm not at all bitter.
The morals: Be prepared for a group interview - I don't know if they still do those, but to me they're much harder than individual interviews so it's best to prepare for the hardest ones. We'll all hope that your store manager not only likes his job, but wants his employees to also like their jobs. Give yourself at least three hours for the interview, and have your work availability ready (oh yeah, they told us that we had to commit to our availability times that morning, and if we changed it in the first six months we'd be fired). And call them every day after the interview to ask if you got the job, cause they probably won't call you.
Good luck!