I am currently writing my latest tutorial which is nearly finished after weeks of hard slog. It involves making samples, taking photographs, drawing diagrams, writing instructions and laying out the pages. Unfortunately for me, I get very fussy and nit-picking and I am compelled to keep making improvements. I'm not totally convinced about the colours on this cover so it might change.
Hewit's have just started selling some of my e-book tutorials. You can find them here: http://www.hewitonline.com/E-tutorials_s/97.htm