The 2014 version of Dreamweaver CC made some changes to the user interface. This is one of them, which, in my opinion, is less than ideal.
You need to click the "add property" button under Custom, and type in the name of the property. You'll get code hints for the property, but not for the value, which needs to be typed in manually.
This tutorial series and my video tutorials were created for the original release of Dreamweaver CC in 2013. I'm not sure if or when Adobe plans to update them (I'm a freelance writer/trainer), but I'll try to help you out if you encounter further issues due to changes in the program.
So for this part:
" 4.Click the grayed-out value next to the list-style-type property (it's the last item in the Properties pane), and select nonefrom the menu. The bullets disappear from the unordered list."
Do I want to have 'list-style-type' in the add property box, and 'none' in the add value box?
Yes, that's exactly it.