You'll be sorry.
Just kidding. You don't have to keep it regularly updated, just doing what you have suggested is enough. As people 'like' your page, every update, however often you post them, appears on their own feed. The point is, for any business it's easy marketing and will spread through 'word of mouth', or whatever the e-equivalent is called, with little effort on your part. You'll get feedback through comments, probably more so than on forums, so you'll need to set time out to monitor it, but that needn't be a chore either.
Listen to your son, it's surprising how many quite simple things there are out there to use.