I'll probably do it again this year (I've done it once before, several years ago--I signed up a few times in the intervening years but never managed to get out of the gate, so to speak). I honestly don't know how invested I am in the idea of NaNoWriMo itself right now, but I plan to be writing a novel anyway and it'll be November, so might as well, right?
Regarding the research question: One strategy I've used (not just during NaNoWriMo; whenever I don't want to lose momentum) is to just leave notes for myself in the manuscript and move onto the next scene/chapter/etc: a brief note about what it is I want to research and what its supposed to do in the scene, and, if necessary, what the scene itself is supposed to do. I usually put these notes in square brackets so they're obviously not prose, and start those notes with the initials TK (these letters almost never come up together, so this makes it easy to search the document for any spots marked TK, rather than scrolling through a novel's worth of pages to find the scenes you need to adjust).
If anyone wants to know, my username on the NaNoWriMo forums is Raethe.