Resource is not present in the OPF error. Use our trouble shooting guide to decipher e-book errors in SIGIL.
Create Logical TOC, Set Meta Data in SIGIL
Two important items add functionality to your ebook — The Meta editor, describes the cover, toc.ncx, name of book, author, etc and the TOC Editor, which adds a logical table of contents to your ebook.
Renaming XHTML Files in SIGIL for EPUB and Kindle
Video 5 DIY Formatting Kit. Use this How-to video to prepare your ebook for upload to Kindle and Barnes & Noble. "Format Once – Use Everywhere™. Visit UnrulyGuides.com for more e-formatting, marketing and promotion tips and tutorials.