Once I painted the base and the plywood board with two coats, I let it dry overnight. I screwed the top board onto the base with two screws, I also added some wood glue for good measure.
Before adding my text, I rubbed the entire surface with a piece of white chalk...then I typed my design on my computer and printed it. I taped down the top edge in case I needed to line up the paper with the blackboard...using a ball point pen, I traced the printout carefully. Then used a chalk "bistro" marker on top.
Initially, I did not intend on this being a double sided project (although I had already painted both sides of the board, so I COULD.) I realized that my son has a birthday just a few days before Halloween, so I should also include a birthday countdown....so I completed the process a second time, just printing out the text on the computer, tracing over with a ball point pen, followed by the bistro marker.
It was that easy! Now I just need to remember to actually count down each day.