And I've made a step-by-step guide thingie mabob to help you out. Hopefully, it [i]does[/i]
1. Go to 'My Mibba'. On the right near the bottom, there's a section titled 'Stories'. Underneath that, should be 'My Stories'. Click that.
2. On the left, there's a linkage titled 'Add New Story'. Click that.
3. Fill in EVERYTHING. Otherwise, you won't be able to post it.
4. It should bring you up to a new page, where your story is now listed. Click on the title, then down near the bottom on the left, should be a thingie that says 'Add Chapter'. Click that.
5. Fill it in, then submit. VOILA! Your story should appear. ^_^