This project is great for little ones because they get to stick, stick, stick, and at the end you can actually say that they were the ones who really made it. Ava made hers at the end of Storytime at our local library. Unfortunately, I didn't take a picture of it before we gave it away to Grandma, but the stained glass window pictured here (stolen off the Internet) is very similar to Ava's.
1) Cut a frame out of construction paper or cardstock.
2) Cut two pieces of contact paper the same size or a little smaller than the outer dimensions of the frame.
3) Cut different colors of cellophane into pieces or shapes. (Older children might enjoy doing this step themselves.)
1) Peel the backing from one of the pieces of contact paper and lay it on the table (sticky side up!).
2) Next, attach the frame by lining it up and laying it on top of the contact paper.
3) Now your child can go crazy placing the different pieces of cellophane all over the contact paper.
4) When junior is finished, remove the backing from the the second piece of contact paper and lay it (sticky side down) over the layer of cellophane. Now the colors are sealed in. Finish by trimming any stray cellophane pieces that ended up sticking past the edge of the frame, and Ta-da! Pretty artwork for your window (or Grandma's)!