Here's the truth about publishing: you don't need anyone's permission to publish your stories. This is the advice, the truth, I give to my workshop writers. But (and this is a big but), you owe it to yourself and your supporters to refrain from unleashing crap on the world. This means taking certain steps before you jump on the self-publish bandwagon.
To avoid publishing garbage, you must ensure your story goes through the same rigorous process as that of a traditional publisher. Your story must be professionally edited. The cover must be professionally designed. And you need to have a story that readers are interested in.
Accomplishing these things takes time and money. If you haven't discussed your story in a good, honest writing circle (not just your friends), and you haven't sent it to beta readers for feedback, then you must do this. Why? Because your story will improve with feedback. Readers and other writers will point out things you have missed, and how to make your story even more effective. I see this all the time in my workshops.
Along with reader feedback is the need to have your work professionally edited. Yes, you are responsible for doing much of this revising, but at the end of the day, you must have a pro look it over and offer suggestions. This will clear up any grammar, spelling, or structural problems your story has. There is a cost to it, but again, you owe it to yourself to spend the cash and get it done properly. What could be worse than spewing out a story full of spelling mistakes and awkward sentence structures? Don't try to go cheap. Do it right.
If you mimic the same actions taken by traditional publishers, you can be proud of the story you send out into the world. Many independent authors are making good livings doing just this!