A Piano: An acoustic piano is preferred, though digital pianos and electronic keyboards offer an wonderful alternative for the beginning pianist.
Music: SheetMusicPlus.com offers the most extensive catalog of piano books and sheet music on the web. Before purchasing your first book it is best to consult a piano teacher.
If you are excited to get started, though have not yet found the perfect teacher, you can begin by mastering the basics, including basic musical symbols, note naming, rhythmic values and intervals. The following websites offer a wonderful collection of resources for the beginning piano student.
Fast Keys is a great, free tool that allows you to learn to sight read very quickly.
MusicTheory.net is a well respected resource for online music theory tutorials and drill and practice exercises.
MakingMusicFun.net is a wonderful resource for free printable note naming worksheets, interval worksheets and music theory arcade games to drill basic skills.
Piano-Play-It.Com Contains a free collection of the most famous and popular pop songs for beginners.
The Rainbow Piano Technique helps young beginners to start playing from scores based on matching colored notes and keys. The website contains a video tutorial that explains the technique and its use.