Anyone who's anyone knows that Amazon's Kindle platform is pretty much the standard for getting your ebook out there. I won't discount Google and Apple's own online book shops, but Amazon's streamlined process is the most accessible. And my very own Kindle Publishing Guide was made specifically for you, so you can publish your own ebook with ease. 
If you're resistant to ponying up for Amazon's $0.99 fee, just send me an email and I'll give you the PDF. No sweat, okay?