Way before you begin the actual writing of a novel (for at least the serious writers), you've gotta do a ton of research (if you're serious about writing authentically).
Let me give you an example:
My suspense. I did research on the following stuff:
Nature, trees, flowers, climate, geographical land, rocks, echoes
Montana's protected species
Colleges from Montana
Fines and punishment for hunting out of season
For one romance book, I researched:
Hot Air balloons
Apples and orchards
Beginning from scratch to build furniture
Is it necessary to do all that? For me, yes. I may only make a single reference to an item. Sometimes more. But I want to have my facts fairly straight. Gives me more credibility. Sometimes, something will never get mentioned, but it helps me know my character better. Why he does this. Why she chose a certain thing.
One problem with research for me is that I get sidetracked if I'm not careful. I might be researching a certain park area, and come across something that is totally fascinating. Woe is me then! If I'm fortunate I'll get away from that with nothing more than some interesting information. The worst case: a new idea for another book!
Only after (and sometimes while I'm writing) do I feel capable of moving on to the actual writing business.
It's a lot of work. But it's fun and informative too.
Well worth the time and effort.
The will to win is worth nothing unless you have the will to prepare.