These are usually located near the office or main entrance, or perhaps even the cafeteria.  Again, most elementary school students don’t frequent these displays, but some parents do, especially those new to the school or the area.  Place some flyers there with basic information about joining Scouting, and contact information for your Pack’s Cubmaster or other designated individual.  A supply should be maintained year round.  You probably don’t need a large supply, just 20 or so, and restock as needed.