Restoring My Ipod Nano (7 generation)

Ok, I went into the apple store yesterday and a lady reset my ipod so that all the songs on my ipod were gone but not iTunes. She told me that I could just sync my songs back onto my ipod when I got home but when I plugged my ipod into my computer it said that I had to restore my ipod. I later found out that she had formatted my ipod to a Mac computer instead of windows. So now I have to restore my ipod. Earlier I moved all of my songs onto 2 flash drives so the songs are there, backed up. Before I restore my ipod I have some worry questions I would like to get off my mind:

1. A flash drive is a way to back up music right?

2. When I restore, will all the songs in my iTunes media folder disappear too?

3. How do I move my songs back onto iTunes from my flash drives?

4. How do I move my songs from my flash drives to the iTunes media folder? (if all the songs in that folder disappear)

5. How do I move my songs from the iTunes media folder to iTunes? (if the songs in the folder don't disappear)

6. Will there be an option about formatting when I restore my ipod or will it format to windows automatically?

Thank you! Please help, answer quickly and give as many explicit directions as needed.