Good luck!
The local radio shack has some great guys working there and they are always very helpful (with anything not pertaining to hobby circuits
) and it is a real pleasure to go in there and get actual personal help with a purchase. So much so that I tend to prefer to purchase many consumer electronics there. They get a lot of business from me.
Anyway...
You may already know this stuff -- in which case I apologize, just trying to help... but... I always found it helps to prepare for an interview -- make sure you know your strong points and can give examples of accomplishments, skills, and how you've benefited the companies you've worked for in the past. If they ask about weaknesses give 'em an example from the (distant) past of a flaw that you've since worked on and improved and tell them how you have learned and improved, etc.
Come up with questions for them pertaining to how you can help them. It can sometimes help to ask a question like "if I were hired, tell me what a typical day would be like" -- which kind of helps get them thinking about what it'd be like with you on board. I would think if you demonstrate that you're friendly, eager to go the extra mile, interested in the job, etc., it will help.
The book that really helped me with landing one really great gig and my current stellar dream job was The Everythign Get A Job Book... great advice for all aspects of the search! Esp the interview.
Cool dream re: having your own store... hang onto the dream! You can totally make it happen!! Step by step, yknow?
Let us know how it goes!!
Michael