I find that some beginner students just can't remember the names of notes, so I made these cards for treble and bass clefs.
Beginner Keyboard Charts
You should be able to print the Keyboard charts onto A4 paper at 100%, and then simply cut it. I print it on to card.
Keyboard for Learners
The Keyboard for Learners is an A3 document - printing onto A3 at 100% should give you a full-size replica of a couple of octaves of a piano keyboard. I trim this so that I can slide it between the end of the keys and the fingerboard on the piano.
Other resources for pianists can be found here.