Pathfinder is a new young adult science fiction/fantasy novel by Orson Scott Card. It is not quite of the same quality as his other works, although his writing style is unmistakable. While it is a good book and I would recommend it to any science fiction fans of the ages 14-18+, I would not recommend it before recommending some of his better books, most obviously Ender's Game.
The novel follows two different stories; the primary one is the story of a young trapper, Rigg, who has a unique talent of finding paths -- that is, he can see glowing paths showing where every person and animal has walked, going back thousands of years. This is not an obviously magical world, and Rigg must keep his talent a secret. This is not hard to do, as he and his father live their lives as trappers hunting in the woods, only coming back to town to sell furs every few months.
Things change suddenly when Rigg's father dies in a freak accident, leaving Rigg with a cryptic message telling him that he must find his sister, a sister that he had not known existed. Thus begins Rigg's quest, during which he will see much of the world, have many adventures, and develop his skills in ways he had not known possible. Along the way he finds others who have unexpected powers, and even a few that have powers that work well with his own.
This storyline is set in the distant future, but in a society that has devolved from its heyday and now appears to be close to a pre-industrial Europe. The 'magical' talents are are theoretically not magic but some trait that has evolved to allow humans to manipulate the universe in new ways. The talents mostly involve some sort of ability to manipulate time.
The other storyline is comparatively brief; it follows a young starship pilot who is piloting one of the first interstellar ships. He will be testing out a new star-jump drive that has only been modeled theoretically, one that really should be tested before being attached to a full-sized ship. But Earth has only recently escaped a mass-extinction from a rogue asteroid, and there is a strong drive to get off Earth ASAP. The ship is carrying everything and everybody needed to set up a permanent colony. Not surprisingly, something goes odd during the jump, and the ship is somehow split into multiple timestreams, with consequences that even the crew can't really begin to understand.
The book is rather light on science, and thus also on science fiction, but officially contains no 'fantasy'; this magic is just sufficiently advanced physics, and, apparently, genetics. On the other hand, story is very logical; the people are extremely sensible, the characters work through the implications of their powers very methodically and in (perhaps too much) detail, and the folks in charge are nothing if not clinically analytically. This becomes somewhat annoying at times, and slows down the action a bit.
Orson Scott Card set out, in part, to build a story around interesting and non-traditional forms of time travel -- the ability to see the past, or to jump backwards in time, and so forth. This is all okay, but he is a bit obsessed with how these powers work, and spends a lot of time analyzing them. They are rather confusing in their execution at times, and as noted, they don't come across as being based in science. They do make for an interesting plot, though, and if anyone can carry off such oddness, it is Orson Scott Card.
Overall, this is a good book, engaging and fast moving, in addition being rather intelligent. But it is not as good as Card's usual books. The story is basically Ender's Game re-written in a new setting -- which is true of many of his books. Overall, I wouldn't recommend hunting down this book unless you've read all the other Card books available to you. I will also note that his other book that came out recently, The Lost Gate is perhaps a better read, and has a lot of the same basic story elements. TLG is not, however, written for young adults.
The sequel to Pathfinder is Ruins, and it is due out in time for the 2011 Christmas season. Explaining the basic setting would provide minor spoilers for Pathfinder, so you'll have to read about it in its own node.