As far as TOCs and eBooks go, just hope the eBook was formatted well. I'm not sure about printed books as we never see the files for those, but a LOT of eBooks I've peeked inside of look like they were formatted by idiots. I'm talking about professionally marketed eBooks (ePubs and mobis) marketed by big name publishing houses. You would think these publishers would hire competent technical staff that understand why it is best to format documents in a structured manner, but sadly they don't. If the formatters of the eBook consistently use accepted tags like H1...H6 for headings, then it is fairly easy to generate TOCs. If instead they are inconsistent with the tags, or they use non-tradition tags for headings, then generating the TOC can be problematic depending on which editor you use. I've seen headings made from DIV tags, P tags with various classes assigned, and other non-traditional formatting. Although this formatting might generate the desired formatting results as far as appearance, it typically confuses the editing software.