This article is from the Piano General Topics FAQ, by Isako Hoshino firstname.lastname@example.org with numerous contributions by others.
There are two books reported so far. The definitive classic
is "The Literature of the Piano" by Ernest Hutchison, which
was written in the early part of this century. For the most
part, this book sticks to the traditional Classical and
Romantic repertoire, though there is also an interesting
discussion of Bach and the pre-Baroque composers. The
revised edition, updated by Rudolph Ganz, adds useful
sections on more modern composers, as well as commentary on
the older material. There are even a few places where Ganz
takes Hutchison to task! The two also make recommendations
for selection of repertoire. Overall, it is a wonderful
book which is not just for reference, but can also be read
cover to cover.
A more recent book is "The Art of the Piano", by [???]. This
book is more encyclopedic in nature than "The Literature of
the Piano", and it does not try to recommend particular
works, as "The Literature of the Piano" does. Therefore, it
is strictly a reference work, but it is more complete. In
particular, there is detailed information on modern
compositions written after the publication of "The Literature
of the Piano". Unfortunately, nothing before Bach and
Scarlatti is listed. There is also an encyclopedic listing
of pianists in this book.