How can I paint concrete pavers with scenes?
The one word answer is "Paint." If you're just going to hang them on a wall as art, then you're done.

But I'm assuming you're still going to be walking on the pavers after painting them, so it's not quite that simple and you'll need very durable outdoor paint, and/or a durable clear topcoat to protect the paint from wear &amp; water &amp; sun / UV damage. Perhaps:


Outdoor art paint &amp; clear coat, this "PAINTED ROCK GARDEN MARKERS" site recommends 


  
  Patio Paint or outdoor craft paint
  Patio Paint clear coat or clear outdoor sealer
  

A deck finish like Natural Clear Transparent Waterproofing Exterior Wood Finish
"A 1-2 punch consisting of an epoxy sealer and a marine varnish" - the page says it's great for weathered wood, but it should be good over painted stone as well.


Whichever finish you choose, be sure to check that it's compatible with the paint you use.