Constant Content

A few times I have had articles bounce back due to not having hard returns.

When I do numbered or bulleted lists and want new paragraphs under each number, or when I complete a bulleted list and want to be back at the margin I usually hit shift/enter and then another enter so that my next paragraph isn't numbered or bulleted. Is this what is causing the problem - the shift/enter?

How do you make a numbered list with paragraphs within a point that line up with the original indented point?

If you press return (i.e. a hard return) twice in Word, it will delete the 'spare' bullet that it put in for the line you didn't enter text into. As you have found out though, it will also stay indented. This is because the style of that line has generally stayed as a bulleted line style. You need to change the style for that line back to whatever the main style of your normal paragraph text is, e.g. Normal or Body Style, etc.
The key to using Word successfully is to master styles and to be in control of what styles are in use at all times. One of the worst things you can do is to change the format of text as you go along by adjusting point size, font, weight, etc, as this creates a new style every time you change something. Ideally you want to have a template with set styles that you don't deviate from.
I tend to use Notepad for CC articles and upload only txt files. This has a number of advantages. Firstly, no formatting to catch me out and secondly, no transferred formatting for the customer to worry about when they copy and paste into their HTML editor. Some editing applications will retain the styles/formatting from Word and it's a pain to get rid of, especially if the webmaster is working in a WYSIWYG environment rather than on the source HTML.