When buying a hamster it is best to get animals from a well established breeder. I do not recomend pet shops unless they are very clean.
Before purchasing you should note the cleanliness and living conditions of the animals. If the cages are clean and the animals appear happy and well kept, then this should reflect the quality of the animal. Avoid getting a hamster from sources such as small cramped pet shops. If you intend to breed hamsters then it is best to visit a breeder to help you get hamsters. What you should look for in a hamster:
It should be in the age range of four to eight weeks of age.
Its cage must be clean with water and food.
Select a color which appeals to you.
The nose should be dry to moist with no discharge.
The eyes should be round, wide open and clear with no sign of staining the fur.
The fur should be smooth and unbroken with no signs of breaking.
It should have an alert inqusitive manner and not be alarmed by handling.
For first-time owners you may find purchasing a male hamster is preferable.