Before we export to ePub from InDesign, there are some import issues to understand. To get the best results for the ePub, we must be sure to provide appropriate tags for paragraph, character and object styles.
We do this through the 'Export Tagging' panel of each of the style dialogues. This is also where we decide how InDesign will split the ePub.
Fo our convenience we can set all of these together through the 'Edit all Export Tags Panel'.
Including exporting to XML and viewing in TextWrangler
In our InDesign document all content needs to be attached to an appropriate style element.
We can use:
paragraph styles
character styles
object styles
table styles
We then need tags that will be mapped to those elements. They can (optionally) be the same names as our InDesign styles. They may also come from a DTD uploaded to our InDesign file in the structure pane.
With a Shakespeare play in mind we have a DTD that we can import into InDesign. This provides us with the TAGS. If we name our styles with those same tags, we can 'map the syles to the tags' very easlily.
Unfortunately, InDesign does not provide us with the automation to map object styles, so we need to add those in to the structure.
Please NOTE: I no longer recommend the use of PDFXML Inspector from Adobe and this presentation covers the use of InDesign version CS5 not CS5.5 which has significant improvements in regard to ePUB export..
You may also want to watch the instructional screencast on the same subject.