Easy chord sheets

There's probably a million songs with only three chords, as I'm sure you know as a piano teacher.    This has come up in the past on the forums, so you may want to look though some of the topics, as people have made suggestions in the past.  If you have an idea of what KIND of songs you're looking for (pop, country, folk, kids songs?), other members may be able to help with suggestions.  2 chord songs that come to mind ... Tom Dooley and He's Got the Whole World in His Hands 

Here's some details about HOW to use Chordie:
You can search via Song Title ("Songs" link at the top) or Artist/Band Name ("Artists" link at the top) alphabetically.  Once on one of those pages, simply click the letters for alphabet sort.  You can also further limit your search from the "Songs" link to "Easy Songs Only" to help with finding more 3 chord songs. 

Of course, from the "Home" page you can search in the box by simply typing (song or artist search is active).  And then... there's the "Public Songbooks" and options for searching there.  You may want to seek out "Absolute Beginner" books that other members have published.  "Books" consist of songs people have found and saved to a list, and then named and published to share with others.