This is a complete solution to the puzzle so be careful how far down you scroll if you don't want it spoiled.

The spoilers start after the first empty grid [if the grid itself isn't a spoiler, in your opinion].

This puzzle is interesting in that you really should have a piece of paper to record your answers, but if you procede logically you can actually do it without any erasures or corrections.
Facts:
1. There are 5 houses of 5 different colors arranged in a straight row.
2. Within each house lives a different owner, all of a different nationality.
3. Each of the 5 owners drinks a different beverage, smokes a different brand of cigar, and keeps a different type of pet.
4. You are facing the row of houses and read left to right.

Hints:
1. The Brit lives in a red house.
2. The Swede keeps dogs as pets.
3. The Dane drinks tea.
4. The green house is on the left of the white house.
5. The green house owner drinks coffee.
6. The owner who smokes Pall Mall keeps birds.
7. The owner of the yellow house smokes Dunhill.
8. The owner living in the house right in the middle drinks milk.
9. The Norwegian lives in the first house.
10. The owner who smokes Blend lives next to the one who keeps cats.
11. The owner who keeps horses lives next to the one who smokes Dunhill.
12. The owner who smokes Blue Master drinks beer.
13. The German smokes Prince.
14. The Norwegian lives next to the blue house.
15. The man who smokes Blend has a neighbor who drinks water.

The Question:
Who has fish for pets?
Solving:
  Left <------------> Right
  House 1 House 2 House 3 House 4 House 5
Colour          
Nationality          
Cigar          
Beverage          
Pet          

SPOILERS START HERE!

8. The owner living in the house right in the middle drinks milk.
9. The Norwegian lives in the first house.
14. The Norwegian lives next to the blue house.
  Left <------------> Right
  House 1 House 2 House 3 House 4 House 5
Colour   Blue      
Nationality Norwegian        
Cigar          
Beverage     Milk    
Pet          
4. The green house is on the left of the white house.
5. The green house owner drinks coffee.
  Left <------------> Right
  House 1 House 2 House 3 House 4 House 5
Colour   Blue   Green White
Nationality Norwegian        
Cigar          
Beverage     Milk Coffee  
Pet          
1. The Brit lives in a red house.
7. The owner of the yellow house smokes Dunhill.
11. The owner who keeps horses lives next to the one who smokes Dunhill.
  Left <------------> Right
  House 1 House 2 House 3 House 4 House 5
Colour Yellow Blue Red Green White
Nationality Norwegian   British    
Cigar Dunhill        
Beverage     Milk Coffee  
Pet   Horses      

Unused Hints so far:
2. The Swede keeps dogs as pets. [House 4 or 5]
3. The Dane drinks tea. [House 2 or 5]
6. The owner who smokes Pall Mall keeps birds.
10. The owner who smokes Blend lives next to the one who keeps cats.
12. The owner who smokes Blue Master drinks beer.
13. The German smokes Prince. [House 2, 4 or 5]
15. The man who smokes Blend has a neighbor who drinks water.

Remaining nationality[house #] combinations:
a) German[2], Swede[4], Dane[5] OR
b) Dane[2], Swede[4], German[5] OR
c) Dane[2], German[4], Swede[5]

Test for a) with Hints #2, 3 and 13 applied:
  Left <------------> Right
  House 1 House 2 House 3 House 4 House 5
Colour Yellow Blue Red Green White
Nationality Norwegian German British Swedish Danish
Cigar Dunhill Prince      
Beverage     Milk Coffee Tea
Pet   Horses   Dogs  

Hints #10 and #15 are now in conflict. The German cannot live in House 2.
Therefore the Dane resides in House 2.
3. The Dane drinks tea.
  Left <------------> Right
  House 1 House 2 House 3 House 4 House 5
Colour Yellow Blue Red Green White
Nationality Norwegian Danish British    
Cigar Dunhill        
Beverage   Tea Milk Coffee  
Pet   Horses      
12. The owner who smokes Blue Master drinks beer.
  Left <------------> Right
  House 1 House 2 House 3 House 4 House 5
Colour Yellow Blue Red Green White
Nationality Norwegian Danish British    
Cigar Dunhill       Blue Master
Beverage   Tea Milk Coffee Beer
Pet   Horses      
13. The German smokes Prince.
  Left <------------> Right
  House 1 House 2 House 3 House 4 House 5
Colour Yellow Blue Red Green White
Nationality Norwegian Danish British German  
Cigar Dunhill     Prince Blue Master
Beverage   Tea Milk Coffee Beer
Pet   Horses      
2. The Swede keeps dogs as pets.
  Left <------------> Right
  House 1 House 2 House 3 House 4 House 5
Colour Yellow Blue Red Green White
Nationality Norwegian Danish British German Swedish
Cigar Dunhill     Prince Blue Master
Beverage   Tea Milk Coffee Beer
Pet   Horses     Dogs
6. The owner who smokes Pall Mall keeps birds.
10. The owner who smokes Blend lives next to the one who keeps cats.
15. The man who smokes Blend has a neighbor who drinks water.
  Left <------------> Right
  House 1 House 2 House 3 House 4 House 5
Colour Yellow Blue Red Green White
Nationality Norwegian Danish British German Swedish
Cigar Dunhill Blend Pall Mall Prince Blue Master
Beverage Water Tea Milk Coffee Beer
Pet Cats Horses Birds ??? Dogs
Question: Who has fish for pets?

Answer: I do. While this an interesting logical exercise, there's no mention of fish in the Facts or Hints! This may just be an oversight or a test of the powers of observation, but I'm not taking it for granted.