You can read the Smashwords Style Guide and attempt to do the formatting yourself. It is looong, but it is thorough. Or you can take a look at my Smashwords Formatting for Dummies posts and try to walk through it. Those are absolutely free for you to peruse at your leisure.
That being said, my Smashwords rates. Now that Smashwords accepts ePub files, I do not like to do Smashwords Word docs anymore. If you want to hire me to format your Smashwords file, it will be a fully formatted ePub. If you’d prefer a Word doc, just let me know when you book me.
For novels under 100k words:
For novels over 100k words:
I reserve the right to charge extra if there are an abnormally large number of chapters or special formatting elements.