This article is from the Piano General Topics FAQ, by Isako Hoshino firstname.lastname@example.org with numerous contributions by others.
Ward Cannel & Fred Marx, "How to Play the Piano Despite Years
of Lessons: What Music Is & How to Make It at Home", Hal
Leonard Corp. ISBN 0-385-14263-3, $17.95, (Video: $39.95,
Useful especially for someone just beginning to play by
ear (assumes knowledge of basic musical notation, melodies
Hal Leonard Corp.
7777 W. Bluemound Rd.
Milwaukee, WI 53213
James Friskin and Irwin Freundlich, "Music for the Piano,"
Dover Publishing. ISBN 0-486-22918-1, ~$10
Book on piano repertoire