Purebred, Crossbreed or Mongrel  
The Six Groups of Dogs  
The Advantages of a Purebred Dog  
Crossbreeds and Mongrels  
Male vs. Female  
Large and Small Dogs  
Long-Haired and Short-Haired Dogs  
Puppy or Older Dog  
Some Pointers on Picking the Individual Dog  

PUPPY OR OLDER DOG

There should be no question about this. Get a puppy in the 7- to 10-week-old group. There's certainly more work involved in raising a puppy, but when he grows up, he'll be the product of your care and training. And this care and training starts with the day you bring him home. It may be possible to teach an old dog new tricks, but you're going to have a lot of headaches doing it.