I am planning to publish (on the web) a book about the life of my Grandfather that was finished but never published and is not likely to be published as this kind of life story no longer sells well enough for a publishing company to take it on.

Anyway, the problem I have is that I want to be able to format the document/s for various applications, so that it can be read on-line or downloaded as maybe a Word document or pdf (probably one per chapter). I don't want to have to re-format the document for different applications, as it is bad enough that the book only exists in manuscript form and will have to be typed (or OCRd) in the first place. It is around 800 A4 typewritten pages.

Any suggestions as to how I can make this work would be appreciated.