Ask HN: What's a good resource to get comfortable with SIMD?

I would like to be proficient at identifying places for and applying SIMD in my C/C++ programs. The domain is primarily centered around graphics, but I am open to resources from other domains too.

Ideally what I would like is some sort of progression for problems that may benefit from application of SIMD. From reading case studies online, it seems like there's lots of little tricks and stuff, almost like there's a different way of thinking about types, values and operations on them that you have to know.