Congratulations on allowing your child to experience the joy and many benefits learning and playing piano! The following items are a must to provide the best learning experience for your child.
An adjustable bench. https://cpsimports.com/Index.html
A piano (preferably acoustic), or daily access to a piano.
I strongly recommend investing in an acoustic piano rather than a keyboard. A student who is practicing on a keyboard at home cannot fully apply what is taught at the lesson, because a keyboard does not have the same touch or response as a piano. If you are not ready to invest in a piano, renting a piano is a great alternative.
Faust Harrison in Fairfield, CT, and Steinway also have rent-to-own programs. If you're looking for an upright, it is best to invest in one that is at least 48" in height, as they have a much better sound that something shorter, like a spinet.
Here are links to local piano showrooms.
Buying a piano is a big investment, and it's important to do research so that you're well-informed when making a purchase. "The Best of Piano Buyer" by Larry Fine is an excellent resource, and there is a supplement that provides a price guide.
Lastly, and equally importantly, is that your child will need your presence while practicing and your support. Most young children require parental supervision on a daily basis while practicing. Parents are always welcome to observe their child's lesson to learn what is expected in home practice. Students often need encouragement when they hit a plateau, or become frustrated with a skill they are trying to master. Learning to play a musical instrument is challenging, but if you encourage your child to work through the challenge, he or she will be rewarded with the joy of being able to play piano!
Dedicated, Professional Piano Instruction
Roxane Lee, M. S., Nationally Certified Teacher of Music