The Legacy of Dragons series by Jack Campbell is probably one of the best sci-fi series I've read since the Thrawn trilogy by Timothy Zahn - and that's including Dune, which I think is really saying something.
I was surprised by these books in a lot of ways, not the least of which is that I didn't realize that this was a sequel series until I was already two books in. It references itself so thoroughly that I didn't realize the stories before this one had their own books. I suppose that might not make sense. Let me put it this way: instead of shying away from describing events in previous books, like a sly nod and wink to those that were already "in" on the secret of the previous books, and without recapping so it felt like a "LAST TIME ON DRAGONBALL Z" voice-over, the events of the previous books were just... there.
Yes, the events in the previous series (series-es?) are integral to the main character and are brought up frequently in all three books - that's because Kira is the daughter of the main characters from the first books, and the fact that she lives with their history looming over her is a major theme in her character arc.
It's pretty easy to give this series 5 stars overall, because I loved the main characters and the worldbuilding is pretty dang fantastic. There's a rigid magic system, which I'm personally in favor of, and the geography of the world (I've always sucked at geography) feels real. The amount of time the character spend traveling, the way they travel, the things that happen while they're moving from point A to point B... it all adds to the feeling that this world could exist out there.
The books deal with some mature themes, but not in such a way that children wouldn't be able to enjoy the books as well. I know I personally read some much, much more suggestive material as a child and it went straight over my head, but then I also didn't figure out that the missing word in Hakuna Matata when Timon interrupts is "farted" until I was in college, so take that with a grain of salt.
This is definitely one of the series I would recommend to teenage or college-age readers, as it features a main character in the stage of life (age 17-18) that comes with the burden of learning the answer to the all important "who am I?" and "what's important to me?" I think the message behind this series is a good one, and I thoroughly enjoyed reading it.