Hello~! This was easier than a blog post, so here goes:
Make sure that you are on the Lunaescence homepage, which looks like this (click on the pictures to make them bigger):
Once you've made it to the archive, you should log into your account. This can be done in the top right of the webpage, or by clicking on the 'Log In' link under Navigation in the sidebar on the left. This should bring you to your dashboard, which will look similar to the one below (minus the admin options):
Under 'Your Stories' (top of the right column), select 'Add New Story' to add a completely new story, or select 'Manage Stories' if you want to add a chapter to a story that's already been posted. The New Story page should look like this:
Please be sure to read through the site rules before posting your first story. As you scroll down, the options for title, summary, and story text should appear. Luna allows very basic HTML tags, but please don't include any pictures or complicated html tags like marquee in your story.
We are a moderated community, so your story won't appear right away to the public. We have some awesome queue moderators who make sure that everything posted to our archive has proper grammar and formatting. You will most likely get an email when your story has been approved or denied, and if it's denied, you'll be provided with examples as to why it was denied so that you can fix it and resubmit.
If you have other questions, feel free to email me at shade(at)lunaescence(dot)com or send me a pm here.