I have made a few of these simple framed magnetic chalkboards to try to sell at the upcoming craft fair.
They are super easy, just find a frame with a 5x7 opening. Paint it if desired.
Then get some 5x7 shingle flashing. (I found mine in the roofing department at Lowe's. It was awhile ago, so I don't remember exactly how much this package cost, but I know it wasn't expensive.) Paint one side of the metal piece with chalkboard paint and let it dry overnight, then prime it as explained in this tutorial.
Remove the glass from the frame and replace it with your chalkboard surface. Put everything back together.
At this point, your cute chalkboard is ready for use. Get out the chalk and write or doodle to your hearts content.
Add a cute magnet, and this chalkboard can also be used to hold notes, cards, etc.
So cute and so, so easy!!