There may be full-time writers who can finish a book
of broad technical scope in several weeks. I don't know
any who can afford to write technical books full-time,
so I haven't anyone to ask. My own experience is closer to a chapter
a month when I can "dedicate" myself, way less when
life throws a curve or two. Remember that even if you
are writing as an expert on your subject, you'll need
research time, editing, diagraming and so on.
As for that demanding lot of editors, in my experience with
Manning everyone has been very supportive through a
series of delays with my work. My wife developed pregnancy
complications, and those deadlines went wooshing past with
barely a wave from me. Maybe I'm lucky to have an editor
who has kids :)
