While I don't know that there's any official schedule, he does seem to be posting them roughly every couple weeks or so. Making it a regular thing would probably be beneficial, both to us as the viewers and potentially to him monetarily (no harm chucking an ad on a youtube video, so long as it's not overly intrusive)
I usually try and post once a week if I can. My schedule sometimes prevents me from being as consistent as I would like to be. I'm glad that you guys find the information useful though and thank you for commenting. Sometimes I don't know if what I'm sharing is of any use to anyone LoL.