Painted rocks are very easy to do.  You need: - flat and/or smooth rocks big
                                                                       enough to paint on
                                                                     - different colours of acrylic paint
                                                                     -  paint brush

Find some flat and/or smooth rocks and wash of all of the dirt. Then select a rock and paint something on it. Examples are animals, trees, a design of some sort, rainbows, flowers and stars to name a few. Anything you can paint you can put it on your rock.
Now, you don't have to do this but here is a suggestion to make the paint last longer. After the paint drys on the rock, you can put podge-it gloss over top to make it shiny and to make the paint last longer.