Since you've mentioned you previously fiddled with shake/nuke and asked about tutorials involving image processing then I'd suggest that after learning the basics to then have a look around on the internet for tutorials involving OpenCV.
Its used a fair amount by uni's and the like for teaching the principles around working with image processing and computer vision whilst being able to use function calls to implement some of the math rather than bogging you down with it.
It does mean however that you won't be learning the esoteric intricacies of the various SDKs which you may or may not like.