Hi,
There's been lots of posts about where to learn about using multicore hardware. I stumbled across the Multicore Programming Primer from MIT on iTunes U. It was a course run a couple of years ago at MIT for people who already are competent programmers who wanted to get in at the deep end using the IBM Cell processor. While the Cell seems way more sophisticated than the Epiphany processor they covered a lot of material that is general in nature. There are also a number of similarities that would mean that techniques used on the Cell would be equally applicable to Epiphany (e.g. using the DMA channels to prefetch the next work unit while working on the current unit).
It's funny, they talk about the Cell being "bare metal" programming without all the modern conveniences. I'm wondering how they would describe the Epiphany!
nick