Airport Extreme & Ethernet Printer

I just purchased my first MacBook Pro and have been doing a lot of reading & research on hardware & software products. This is also my first posting. I would like to purchase an Airport Extreme and connect it to my existing router. I would then connect an external disk to it via USB. I would like to use this disk for Time Machine backups and file sharing with PC's running windows.
1. Is this possible? If so, should I make 2 partitions (one for backups and the other for sharing files)? Would both partitions use HFS+?
2. I would also like to connect my printer to one of Airport Extreme's ethernet ports. Can I do this? I don't have a USB port on my printer, only an ethernet port. I also don't have any free ports on my original router. If possible, I'm sure I would have to use a fixed IP for the printer. Any adivse would be appreciated.

Thanks,
Ken