For God's sake not Czerny! Hanon exercises 1-10 might be a good little mechanical etudes, each very short as any purely mechanical piece should be. On the musical side Perhaps Fur Elise or Chopin Prelude no4 in e minor. The C major Mozart Sonata "Facile" might be appropriate. Dare I recommend the easy Chopin polonaise in B-flat? (the one he composed at age 7) Of course the Chopin prelude no7 in A major is good too.
What else...the first C-major prelude from Bach's WTK.
Jane Magrath wrote a great repertoire guide, http://www.amazon.com/Pianists-Standard ... 119&sr=8-1
I use mine all the time.