(Credits go to http://animalcrossing.tv/2007/09/hair-guide-on-animal-crossingwild-world.html )
After unlocking Nookington's at Tom Nook's shop, Harriet's hair salon will be available on the first floor. She can fix your hairstyle for 3000 bells for each session. This is very similar to Kapp'n asking you questions during the start of the game which affects your appearance corresponding to your answers. Only one haircut is allowed every 24 hours and if you want to have all of your visitors get a haircut at the same time you have to keep your gates open. After 16 haircut sessions, she will give you the option to choose a hairstyle from the opposite gender.
Below are the hairstyles and colors corresponding to your answers:
Hairstyles
Question: "Hmm. Now tell me, sugar, when do you want your style to REALLY
come alive?"
Answer: "Every day."
Question: "Do you like the sun? How does it make you feel?
Answer: "Warm..."
Question: "If you were rushing to the salon and someone were to call to you,
what would you do?"
Answer: "Grin and say hi!"
Question: "Hmm. Now tell me, sugar, when do you want your style to REALLY
come alive?"
Answer: "Every day."
Question: "Do you like the sun? How does it make you feel?"
Answer: "Warm..."
Question: "If you were rushing to the salon and someone were to call to you,
what would you do?"
Answer: "Ignore 'em!"
Question: "Hmm. Now tell me, sugar, when do you want your style to REALLY
come alive?"
Answer: "Every day."
Question: "Do you like the sun? How does it make you feel?"
Answer: "Sweaty!"
Question: "Are clothes important to you?"
Answer: "Oh yeah!"
Question: "Hmm. Now tell me, sugar, when do you want your style to REALLY
come alive?"
Answer: "Every day."
Question: "Do you like the sun? How does it make you feel?"
Answer: "Sweaty!"
Question: "Are clothes important to you?"
Answer: "Nah."
Question: "Hmm. Now tell me, sugar, when do you want your style to REALLY
come alive?"
Answer: "Big nights!"
Question: "I'll bet you're just the toast of every party, aren't you?"
Answer: "Well, duh!"
Question: "If your ideal hairstyle were a song, what kind of song would it
be?"
Answer: "Power ballad."
Question: "Hmm. Now tell me, sugar, when do you want your style to REALLY
come alive?"
Answer: "Big nights!"
Question: "I'll bet you're just the toast of every party, aren't you?"
Answer: "Well, duh!"
Question: "If your ideal hairstyle were a song, what kind of song would it
be?"
Answer: "RAWK!"
Question: "Hmm. Now tell me, sugar, when do you want your style to REALLY
come alive?"
Answer: "Big nights!"
Question: "I'll bet you're just the toast of every party, aren't you?"
Answer: "Unfortunately..."
Question: "Well, will you tell me a bit about your primping routine?"
Answer: "I'd rather not."
Question: "Hmm. Now tell me, sugar, when do you want your style to REALLY
come alive?"
Answer: "Big nights!"
Question: "I'll bet you're just the toast of every party, aren't you?"
Answer: "Unfortunately..."
Question: "Well, will you tell me a bit about your primping routine?"
Answer: "I'm embarrassed!"
Hair Colors
Choice: Mysterious!
Color: Dark Brown
Warm or Cool?: Cool
Choice: Young!
Color: Blue
Warm or Cool?: Cool
Choice: Lush!
Color: Green
Warm or Cool?: Cool
Choice: Radiant!
Color: White
Warm or Cool?: Cool
Choice: Safe.
Color: Light Brown
Warm or Cool?: Warm
Choice: Lighthearted.
Color: Blonde
Warm or Cool?: Warm
Choice: Fiery!
Color: Orange/Red
Warm or Cool?: Warm
Choice: Flirty...
Color: Pink
Warm or Cool?: Warm