For a young child, you may want to look at a group piano-based music class.
Musikgarten, Harmony Road, Suzuki Piano, and Music for Little Mozarts are
some of these. Some offer both private and group classes (Suzuki, in
specific, I know requires both), but all are designed to be developmentally
appropriate for the 5-7 yr old child and still incorporate the kinesthetic
learning so important for this age group. I do not know of any program,
including Suzuki, which takes children on piano before age 4-5 due to
physical size constrants-you can't scale down a piano the way you can a
violin. My program offers Suzuki strings starting at age 3 1/2, but piano
starts when the children start Kindergarten, or sometimes 1st grade. We have
group classes which use many of the same skills which parents are encouraged
to enroll their child in until they're physically ready for piano, and the
students start listening to the suzuki CDs and attending recitals and
twinkles in preparation with their group pre-piano class.

Good Suzuki studios often have pretty long waiting lists, because there's a
practical limit to the number of students one teacher can teach, so I'd
suggest getting on said list ASAP. We recommend at least a year in advance,
and more is preferable.

--
Donna DeVore Metler
Orff Music Specialist/Kindermusik
Mother to Angel Brian Anthony 1/1/2002, 22 weeks, severe PE/HELLP
And Allison Joy, 11/25/04 (35 weeks, PIH, Pre-term labor)