Hi There, I recently created my own very simple guide based on converting a manuscript to an ebook. As you say there are plenty to choose from out there. My main motivation was to write down my experience of learning how to convert an ebook based on no prior knowledge, mainly so I have a point of reference for any future book conversions. If you want to check out a free pdf copy go to http://www.davidkindertheauthor.com/
. So yes for me I felt writing a guide was worth it, but if your already highly computer literate I am not so sure sure of the market for books with lots of html explanations. I have made no attempt to promote my book other than to publish on Kindle. If someone picks it up and it helps them then great, otherwise it is there so I can remember how I did it in a couple of years time. Good Luck.