I'm in the same boat as you describe, although I have no programming background. (Although I don't know what your background is either) Currently, I am in the process of learning to code as I learn the various API's that are available. I'm an objective-c guy going backwards to the c-based Quartz API, and it's a little bit of a challenge. Luckily, Programming in Objective-C 2.0 by S. Kochan has a great chapter on underlying C features to keep you afloat.
I have taken a couple of stabs @ OpenGLES, and I have to say, that from a conceptual standpoint, I'm not ready for it. The Quartz2d API is a bit easier to learn conceptually because it's very easy to get up & running with a few commands. Right now, I'm at the point where I can define shapes and point to point images with out too much trouble.
OpenGLES is going to be something in my future, but it takes such an enormous amount of code to configure the drawing view, set up buffers, etc. If you are familiar with everything the code is doing, then it's a bit easier. However, from a learning perspective, Quartz is an easier way to get going, quickly.
Resources I'm using: The aforementioned book, and an anemic amount of blogs containing tutorials, which are limited @ best. At this point, make an appointment with the apple docs and get cozy, because it's about the best (free) stuff that's out there (& exhaustive) With that said, I'd love for someone to prove me wrong on this site by posting a great resource for learning, but that's about it. Good Luck.