A prolific authoress, and one who's work has come under considerable question as to whether it's more science fiction with a fantasy cover or vis versa, her books have remained immensley popular both lovers of fantasy and of science fiction. Our own Colleen McAndrew has written a brief primer to her work.
Literary Quality:
Christian Morality: Good/Dangerous
Age Appropriateness: Teenager
Pern: mostly good with the exception of the sexual morality (but that has some redeeming features and is not TOO intrusive). The books about settlement and genetic manipulation, etc., probably need to be considered apart from the earlier ones that start later and are more fantasyish instead of looking into why, how, when. Overall excellent storytelling, although lately the horse is showing signs of rigor mortis.
Space Opera: Sassinak, The Ship Who..., Dinosaur Planet (which blends with Sassinak), Doona, I think I'm forgetting something -- is more varied. Storytelling is good to okay; again the problem with sexual morality -- it gets better or worse from book to book, tends to be worse than Pern. Some -- Sassinak/Dinosaur Planet in particular -- introduce a very little bit of quasi-religious stuff like making it unkosher to eat meat; unorthodox types will eat fish. The Ship Who has children with various physical deformities hooked up to machines very early in life -- I think as an alternative to euthanasia, though I could be wrong -- for the purpose of becoming the Brain of a spaceship, hooked directly into its computers and basically becoming the ship. These are paired, usually for life, with a Brawn, or physical walking-around partner; several of the books deal with what happens when one, usually the Brawn, dies. There's one instance, if I remember right, of a ship gone crazy set up as the object of a religion, but this is so obviously wacky that it doesn't comment too much on religion in general. At least one has some pretty graphic brutality when bad guys take over a space city; that one's not one of my favorites. Doona has a human girl marrying -- or pretending to, I don't remember -- an alien guy and then getting drunk and sleeping with someone else because he wants a son. Also a priest that goes somewhat crazy on a pollen the planet blows around -- this happens to basically everybody -- does some rather unpriestly things and thenceforth stops functioning as a priest because he's doing some penance like piling up rocks. Not really flattering. Overall they're not too bad, especially compared to some of what's out there, but Pern's better.
Other: some more recent little things (such as the Acorna series, kinda fairy-talish, decent morality-wise, pretty good storywise, but too small to really signify.