help with my job interviews

I have interviews for part time jobs, one Thursday for a video game store and one Saturday for a clothing store.
For sure for the interview at the game store I am wearing a suit but the clothing store I’m not so sure because I don’t want to be over dressed and the type of clothes this store sales are all Hip Hop/Urban/Skater type clothes and the employees wear T-shirts, loose jeans, baseball caps…you get the idea, regular street clothes. The assistant manager is only 20 something he hasn’t ever worn a suit to work as far as I know. In fact I’m pretty sure that the store has a “no tie” dress code.
Dopers do any of you think that in going for an interview at a store like this I should still wear a suit or should I do what I was thinking and wear a nice pair of black jeans and a short sleeved button up shirt that I happened to buy from that store less than 2 months ago.
One more thing, if I get offered the video game job on the spot should I just take it or should I say that I have one more job interview and I’ll let you know later.
If I said that would that make them not want to hire me.

Scout out the store. Dress a little more formal than what other employees are wearing.

I’ve rarely been given the offer right at the interview but you may. I have a different perspective and have never turned down a job offer when I wasn’t already employed. YMMV

While my job search experience is more post-collegiate, there are some things that can be used for any job. When I applied to McDonald’s many years ago, I went to the interview with just a dressy casual shirt and slacks. I would think that that would be fine for the clothing store position. If possible, I would even ask some current employees what they would suggest (if you know any of them, or shop there often, for example).

As for a job offer on the spot, I can’t say that I have had that happen to me yet ;), but from everything I’ve read, there is nothing wrong with telling the hiring manager that you need a few days to think about it, to think about the package they are offering you (even if it is only a salary with no benefits). Even a week is fine for longer-term/career jobs, but that may be pushing it with a video game store. You definitely want to avoid giving a specific reason for it (i.e. don’t tell them you have another interview) though. All this may change depending on the job market in your area, so if there are tons of high school and/or college students looking for part-time work, and not many help wanted signs, you will have to take that into account methinks.

A book that helped me a lot for interviewing, resume writing, etc. is It is geared for the entry-level positions post-college, but there are a lot of useful tidbits for any level, from high school, all the way beyond. The entire book is online there, but I found the paperback copy to be great when I was traveling.