I've often said that the biggest thing I’ve learned through working with the SPCA is the best way to get a pet for your family.
The two musts for adopting are:
1) Don’t make an impulse adoption ...and...
2) Do a lot of research to make sure you get a pet that is of the right temperament and energy for your life style.
Family Circle Magazine has a great pictorial on the best breeds for city, suburban, active and not so active families. Good luck in picking your pooch!