Sigil will create industry-compliant ePub files... but not from Word docs saved as HTML. For best results, you'd need to copy your text from Word and paste it into Sigil's doc window (as opposed to the design window), and let Sigil handle the formatting.
If you have chapter headings, Sigil will let you see the list of headings... you can choose which headings will remain in your TOC, helpful if you used subheadings, H2, H3, etc, and don't want them in your TOC. You can also easily add your meta information in a separate window. Then add your cover, and save your file.
It's actually quite simple, and results in excellent ePubs with the least amount of effort. I would recommend trying it, or visit the
Sigil forum here on MR.