Please click on the following links which will connect you to some wonderful articles on the Portuguese Water Dog Club of America Website.  This will help you to determine if this is the right time and or breed for you.

PWD's and kids. http://www.pwdca.org/pwds-and-kids
Mouthiness.  http://www.pwdca.org/mouthiness
Exercise needs.  http://www.pwdca.org/exercise-needs
Time for a puppy?  http://www.pwdca.org/puppy-information