Once your novel is up and running you will most likely be posting directly into the novel. This is done through the Submit Story page.
In step 2 (Story), you can now either select 'Individual Submission' or 'Chapter in a novel'. If you select the latter you will not be able to put in a title, type or genre, but you can select either to submit to an existing chapter of your novel or create a new chapter. Select either and finish submitting your story as normal.
You are free to enter author's notes for this submission if you wish, but once again it's a good idea to use novel-global author's notes instead.
Note the story title on the confirmation step. It should reflect the novel name and the chapter that you are submitting to.
Once you submit the story you can view it and see that it has the title of the novel with the chapter number, name and part as a subtitle.
If you have submitted other parts into the chapter or other chapters you will see the navigation links to the previous or next submissions.
You can click 'View all chapters' to go to the novel page.
Note that submitting into a novel costs the same as normal submissions. If you submit into a private queue however, each submission will always cost 3 credits, regardless of how many submissions you have in the queue.