My aunt lives next door (about 100 yards) she has satellite internet and said that we can share it (me access it from my house) but neither of us are sure what to do on either end. Can someone please tell us what she needs to hook up and do on her end and what I need to hook up and do on my end?

It is illegal for the two of you to share cable. It can also be a jail sentence, fine or both.

It may be illegal to share cable. This isn't a cable connection (it's satellite). However, RuralPrincess47's aunt would be the one held legally responsible for what activity takes place over her connection so any wireless connectivity would have to be very carefully locked down.

That said, if there's a clear line of sight between your two houses, your aunt could install a wireless access point at the side of her house (by a window would be best) facing yours, and use a USB wireless dongle on an extension cable (for best positioning) to connect your computer to her network.

WPA encryption is an absolute minimum, WPA2 is better, and ensure you use a password that nobody could guess. (Get your cat to walk across your keyboard a few times?) This will minimise your aunt's exposure to having any unauthorised connections being made to her access point.