It is self-evident that the more an author puts into a story, the more a reader will get out of it. Solid research will underpin the credibility of what lies between the covers of a book but and help build the trust of readers.
Research leads to writer-confidence in relating key information or capturing the atmosphere of a setting. More than that, it informs the reader by adding to his/her knowledge bank (no matter how subliminal). To do it properly, however, requires a balanced approach and an eye for what is important as opposed to what can be little more than window dressing.
I was once told that just because you know the detail of something doesn’t mean you have to bore the pants of everyone by telling them how clever you are. It’s all very well, for example, that you may know the precise calibrations and mathematic formulae for manufacturing a car engine but do your readers really want to spend time reading about it in a romantic novel, or, for that matter, any other kind of novel? SEE MORE AT: http://joemccoubrey.com/book-writing-how-far-does-author-research-n...
It truly is a balancing act to provide "just enough" detail to draw the reader without forcing them to drudge through information that they find dull or does not move the story along.
For me, the trick is to be subtle about it. Don't write paragraph after paragraph of technical description, rather, work it in here and there. This helps to keep the reader engaged without giving them a reason to skip over what may be an important detail down the road.
I should point out that I am coming from a "Historical Fiction" perspective. Although the stories I write are fiction, most of the detail is true to life and offer a "could have been or could be" scenario.