Playing the keyboard can be a satisfying and enjoyable pastime if you're willing to commit to learning how to play. While few people can play complex classical and jazz music right off the bat, there are plenty of songs fit for beginners.
Books for Beginners
Plenty of "How to play" books are available for the aspiring keyboardist. Many of them teach basic songs, like "Hot Cross Buns," "Camptown Races," and "Mary Had a Little Lamb." While these songs are simplistic in nature, what they really do is help you understand different keys, notes and where to play on the keyboard. Depending on the model, some of these songs may be pre-programmed on your keyboard, allowing you to play along and keep in time with the tempo of the music.
Believe it or not, a number of music teachers post lessons for free online. A simple Google search may be all it takes to find a video lesson teaching you how to play any song of your choosing. Of course, your choices are limited to what you can find, but you're sure to come across classics from "House of the Rising Sun" to an assortment of holiday music.
Songs of Your Favorite Musicians
If you're a beginner who is already starting to get a grasp for pitch, maybe it's time you try playing the songs of some of your favorite musicians. Artists like Billy Joel, Elton John, and Regina Spektor are known for their piano work. Though these songs aren't necessarily easy to play, it sometimes helps to try something a bit above your level to help you advance faster.
Of course, if you find that playing by ear (listening and playing based on what you hear) is too difficult, you can always resort to sheet music. If you're still struggling, don't be afraid to take a step back and try simpler songs. Practice makes perfect, and when you're ready to move to the next level, you'll know.