The Night Angel Trilogy by Brent Weeks. I've read the first two books, and they're very good, although I'd rate them at least on a teen level (there's some nasty stuff that happens, especially in the first book). Depends on how mature the kids are, I guess, and only you can make that call.
Anne McCaffery's Dragonriders of Pern is a good series (and fairly kid freindly), although it skirts the edge between scifi and fantasy. Very low magic (dragons and related creatures have a few "psionic" powers - teleportation, telepathy/empathy, and possibly telekinisis - but the dragons aren't D&D dragons - telepathy is usually limited to just each other and their own rider; there are some other restraints put on their powers as well), and most books have medieval-level technology. Pern is a lost colony that was reduced to medieval conditions thanks to a deadly organism called thread, which rains from space and eats everything. Dragons were engineered from a smaller dragonette native to the planet (think pseudodragon) with the last of their technology to burn up thread before it hits the ground. The original trilogy starts off quite a number of millinium later, with everyone living in castle-like holds and little idea on where they came from.
