You didn't think I would leave you will all that inspiration and no guidance?
If you are using a chalkboard wall for children only, I recommend painting the lower 1/3 of your wall in chalkboard paint. Beware, if you choose to paint the entire wall in a room so that you can use it too, make sure the room gets a tremendous amount of sunlight, or the chalkboard paint will make the room extremely dark. I also like the idea of adding a chair rail with a special ledge to hold the chalk.
Below are some of my recommendations for chalkboard paint options:
Rust-Oleum Chalk Board Paint available at Target