Let's have a look an example. Note that you can you always should make visible the EDD element tags when working on an EDD file (Menu: View->Element Boundaries (as tags) Alternativly you can work with the Structure View Window.
The organization of a simple EDD definition for a typical element is the following:
Element
Tag
Container (many others exist, e.g. graphics or crossref)
General Rule (corresponds to an ELEMENT definition)
Text Format Rules
Context Rule
.. Formatting nested down to many levels ...
The organization of the Formatting Rules corresponds roughly to the organization of FrameMaker's Paragraph Designer (Menu: Format->Paragraphs->Paragraph Designer). You can look at this tool, however do not use it (except for the few base paragraphs from which you will inherit). Also, remember that you always should use "change" something.