"Engines of Destiny" featured Scotty, TNG era. I have not read it, so I don't know whether to recommend it or not.
"Crossover" is okay. A good bit of it focuses on TNG-era Scotty.
As far as I know, the SCE series has some tales that feature Scotty.
I've read both.
Engines of Destiny was awful. DeWeese didn't just butcher Scott's characterization, he butchered everyone's. There wasn't one single character in that book that rang true. No wonder it wasn't published for the longest time... I have NO idea why anyone did eventually. It's that bad.
Crossover was meh. It had moments of good insight, but the author never managed to shake off the 'must hit every Scotty-cliche-and-stereotype in x-number of pages' problem. You'd have an insightful moment (ie, that he's kind of guarded, really), then some absolutely moronic cliche. I was more irritated by Crossover because it DID have some potential, and the author DID show some good insight, but sacrificed really using it so that he could appeal to stereotypes that many (though not all) TOS fans accept without question.
Overall, I'll stick that Kobayashi Maru offers an absolutely interesting view of an 18-year-old Scott -- a rather shy, nervous little bundle of energy who's trying to live by someone else's rules until he gets a chance to live by his own. And Vulcan's Glory, just because I love D.C. Fontana and the idea of Scott serving concurrently with Spock for eleven years on Pike's Enterprise.
There were a few good sets that had him characterized well, mind, but none deeply insightful. The Errand of Vengeance series, for one -- he was shown as being competent, and you could see why he was Chief Engineer of the Enterprise; it managed to draw a well-characterized portrait of Scott without diving into cliches.
...and I'm rambling. But hey! There're my thoughts.