I think this type of content shouldn't be posted on HN. It's not news and it's been a long time since there was any shortage of study aids online.
Besides, the biggest value of HN is not the links or 'news' posted here but the discussions around them.
Surely, not everything on HN is always useful to everyone. But on days when the front page isn't that appealing to me, it reminds me to get back to my work and try and apply what I've learned so far.