To begin learning and playing classical piano, practicing on a piano is optimal.  A piano can be purchased or rented from a music store of your choice, but, actually, a keyboard is all that is really necessary for quite awhile.

Requirements for a keyboard:

1. The keys should be the same width as piano keys (they should not be thinner).
2. It should be capable of touch of sensitivity, which means that if you touch a key softly, the tone will sound soft, and if you touch a key harder, the tone will sound louder.
3. The keyboard does not have to have all 88 keys that a full size piano has.

Music books:

The teacher can supply the new music book to the beginner, which you can purchase from the teacher during the first lesson.  The cost is usually less than $10, depending on the book.  Adult books are a little more expensive.