Help Crocheting

So before everyone tells me off for not using the search bar, I've already done that and it's not helpful. I'd like to refresh my memory on how to crochet hats (I was never very good). Could anyone give me some advice/links/videos etc? I've tried getting into the crocheting cult but have had no luck so far (if someone could explain why no one gets in anymore more that would be nice too). I'm really just looking to make hats for skiing and wearing around and I haven't found much ingot on how to make them the right size etc. I'm not trying to do these for sale, just for myself and my friends. As always, any help would be much appreciated!