Children of the Fleet by Orson Scott Card.
Here is the description from Amazon:
Children of the Fleet is a new angle on Card’s bestselling series, telling the story of the Fleet in space, parallel to the story on Earth told in the Ender’s Shadow series.
Ender Wiggin won the Third Formic war, ending the alien threat to Earth. Afterwards, all the terraformed Formic worlds were open to settlement by humans, and the International Fleet became the arm of the Ministry of Colonization, run by Hirum Graff. MinCol now runs Fleet School on the old Battle School station, and still recruits very smart kids to train as leaders of colony ships, and colonies.
Dabeet Ochoa is a very smart kid. Top of his class in every school. But he doesn’t think he has a chance at Fleet School, because he has no connections to the Fleet. That he knows of. At least until the day that Colonel Graff arrives at his school for an interview.
--This is the start of a new series. I liked it!