Usually, you'll apply online, have a quick phone interview, meet with HR, and if they like you, you meet with a department manager who has an opening/fits in with your desires. Usually the process is fairly quick - it won't be weeks and weeks of waiting between interviews. Took me 5 days to speak with everyone and be offered a position.
Phone interview: Why Nordstrom? Work experience? One or two customer service situations - how would you solve? Literally 10 minutes, at most.
HR: Lots of your basic, "give me an example of a time you had a difficult customer/had to meet a sales goal when it was slow/didn't get along with a coworker/etc" type questions. Asked a little bit about duties at previous jobs, and explained some of the benefits and expectations of Nordstrom.
Department manager: Same questions as HR, just maybe worded differently. It's okay to use the same examples, they don't mind at all. They'll talk to you about their own needs and expectations, and what they want in an associate, their manager style, etc. Will usually take you out of conference room and walk you to their department to briefly talk about product, how to sell, etc. My manager handed me a pair of bright purple shorts (for men) and had me sell them to him. If you can, pair it in an outfit, and they'll fall in love with you.