I'm guessing your playing the wii version (the pc one asks if they like paprica). You have four guest and three questions for each. The questions are as follows:
Side of the bed they get up on
Planet they most identify with
Hometown
Side of the bed they most get up from: You're the maid! When cleaning their rooms in the morning, you will see their slippers on the side of the bed they get up on. ( I will tell you the answers at the bottom though i have heard you have to find them yourself to get them to work)
Planet they most identify with: This one is simple. Ask them! go up to the guests and an option will come up asking them this.
Hometown: this is found in the computer under guest registry.

Aswers:
GC: left, Los Angeles, Earth
LT: Both, Brea, Planet X
BK: Right, Toronto, Mars
YV: right, Eladssaet, Pluto