If I were you, I would definitely look beyond IT related book templates. Correct me if I'm wrong, but everything I can see that makes a book template IT specific is the possibility to quote code, one variation being in block form, and the other within a text like what we have in markdown: $variablename
that is a styling question that could easily be added afterwards.
Finding high-quality templates seems really hard. Maybe the best way is to find a clean basic Word template, and customize it yourself to the desired look and feel. It's not that hard, it's just many small details, and there's nothing wrong with copying some of those details from one's favourite book. (If it gets published by a publishing house some day, it will get scrutinized by a merciless layouter anyway, imported into whatever they use for layouting, and streamlined with their design guidelines. For the moment, it needs to look clean and the way you like it.)
One of the most important characteristics of a book is certainly the font used. Fonts are easy to identify using Identifont, and often affordable to purchase.
Some Googling turns up this range of minimalistic book templates. While it's not Addison-Wesley or Random House, but a self-publishing enterprise, the template looks clean and provides the basics. Maybe it - or something like it - is a start.