Depends what you want to do and what platforms you want to use it on. There are a number of options – they each have their advantages and disadvantages. Two examples, you can produce a nice interactive PDF with InDesign, especially InDesignCS6/CC. Alternatively, there's the Adobe Digital Publishing Suite, they have their own forum: http://forums.adobe.com/community/dps
Thanks DerekC1000, I forgot to mention that I need to develop the IEM in S1000D format. Is In Design compatible?
According to Wikipedia, the S1000D format is an XML specification.
How are you publishing or distributing this document? That is probably not something InDesign could produce.