Working at a furniture store.

One of my characters is a salesman at a furniture store. What I need to know is just basic, day-to-day things. I've tried searching Google, but the closest I've come up with is a discussion on how much money this kind of job makes. I've worked in retail myself, but I'm sure there are differences in operations between stores that sell different things.

Things I'd like to know:

• What kinds of duties do salespeople have before the store opens in the morning? Even if it's boring, actually, especially if it's boring.
  
• Are there different positions for salespeople and clerks (I guess what I mean is, do the people who help customers decide what they want also ring them up and take payment and delivery information, etc.)?
• How long are employees in the store in the morning before doors open? Are the lamps in the floor displays turned off to save power during those periods?
• Are there any specific duties salespeople have while the store is open if there aren't any customers browsing?
• And lastly, what are some of the most amusing stupid customer stories/questions/etc. you've experenced?

Thanks to anyone who can help!