In her dream, Lisa meets the Wild Things from Maurice Sendak's book "Where the Wild Things Are"
Marge complains that the family will be next to a graveyard instead of a stamp museum. Technically, they are living next to a cemetery. The difference is whether or not the property features a house of worship. Since there isn't a church with a churchyard along side of the graves (i.e. a graveyard) This, then is a cemetery and is a standalone property. The terms are sometimes used interchangeably, though.
The five items that Homer pushes out of their bed to make room for Lisa are: Santa's Little Helper, a small portable TV, a blender of Margaritas-half full, a broken off head of a parking meter, and Marge.
At the Springfield Stamp Museum, Bart & Lisa are shown a commercial for the Hillside Wrangler Steakhouse. This is a reference to the Hillside Strangler, a nickname given to serial killers Kenneth Bianchi and Angelo Buono Jr. who killed ten women in LA during 1977-78.