The wikipedia very basic plane
This is another basic airplane most children learn.

(Image licensed under the GNU Free Documentation License, source SVG created by Ysangkok at Wikipedia.)


Step 1:

Fold the paper in half lengthwise.

Step 2:

Fold the top corners down towards the center fold.

Step 3:

Re-fold the paper in half lengthwise, then fold down the wings. Experiment with different wing lengths to see how it affects flight.