The final act is the making of the ebook. As VR, our faithful canine friend, has pointed out there are many tools available to amke this final leap -- BookDesigner, Mobipocket Creator, calibre (used by Fictionwise for all of their Sony format offerings), and even such tools as Dropbook for creating eReader books. Many formats can also be created by most of the ABC Amber line of converters including many of their free converters. I believe that for all of the ebooks that Patricia has posted (1,893 as of this post) and most of the 865 ebooks that I have posted, BookDesigner was the tool employed.
It may take 5 minutes to convert and produce an ebook they way Patricia and I work. What takes the time is the correction and formatting of the source file before using a conversion tool.
For many of Patricia's books she has added/corrected the texts that have been found at sources such as Project Gutenberg. Sometimes whole sections were left out, other times lines are skipped. Many of the books she has posted were from source files that no accent marks on the letters when the original (read hardcover printed versions of the same book) did have such marks. Many of the web available copies of classics are provided using only 26 letter glyphs plus a lower case. Some prep work will almost always be required. Project Gutenberg for example, often indicated italics by enclosing the word or words inside underscores ("_").
VR mentioned that I had also scanned pages, OCRed text, and proofed the result. This is true. I was completing the Harvard Classics
series and certain critical sections were not available anywhere on the web that I could find. What copies I could find of some were often the wrong version/edition, the wrong translation, or were formatted in such a bizarre way that it was faster and (for me) more accurate to start from scratch. I was lucky in that later in the project Bob Russell found and told me about the Internet Archive which offered PDF image files of the original volumes. I posted the original set in Sony LRF, added the Mobipocket and IMP versions later. Nrapallo then converted all of them to the REB 1200 version of IMP. VR added the Reading Guide. See the MobileRead Wiki Notable eBook Uploads page
for more details and links for downloading. There are also references to the Dickens and Austin complete series there.
In short, IMHO, once you have the book corrected and proofed, the rest is easy.