Nemesis... back when the movie came out I tried to get my hands on a copy of the novelization, but was a bit confused because I read somewhere that there are different versions: one that goes beyond what's shown in the movie, and another that just sort of recounts the movie without any further details...
No, all copies of the "Nemesis" novelization are the same, but they do included scripted and extended scenes (eg. Wesley at the wedding, mentioning he'd just joined USS Titan) dropped from the movie. When the two-disk DVD of the movie came out, this scene was in the bonus footage section. Furthermore, Wesley is seated at the far end of the bridal table in the movie as screened, but people who avoided buying widescreen DVD versions missed noticing him.
Then came the "A Time..." mini-series of seven books. In these, a different career path
for Wesley (and for Dr Crusher) was explained, overriding the (non canonical) DVD bonus scenes.
ST novelizations that exist in different versions:
* TMP: the UK and Australasia printings have several brief, extra explanations about Vice Admiral Lori Ciana. And a set of captioned colour photos in the middle.
* ST II/III/IV: The Signature Edition
reprint omnibus ("Duty, Honor, Redemption") fixes Sulu's rank to reflect the rest of the film series; ST II had originally made his captaincy imminent, but the scene was dropped as unusable footage. McInytre had continued this rank chance as a minor character arc through all three books
* Generations: The hardcover has Kirk's original death scene (now a bonus feature of the GEN two-disk DVD.) The mass market paperback has the chapter rewritten to reflect the movie as released (ie. the revised death scene.)