The Warrior's Apprentice is the fourth book I've read in Lois McMaster Bujold's Vorkosigan Saga; but it is the first one to feature Miles Vorkosigan, the protagonist of most of the series.

An assassination attempt on Miles's mother during her pregnancy resulted in Miles being born with extremely brittle bones. Despite this handicap, he attempts to pass the rigorous requirements of the military academy on his home planet of Barrayar. After breaking both his legs in a physical exercise, Miles travels to his mother's home planet to visit his maternal grandmother; but is sidetracked by the adventures he encounters when he buys one spaceship and captures another.  It all leads to political intrigue and an attempt to frame Miles for treason.

I really like the character of Miles - an unlikely hero, given his handicap and his sub-5-foot stature. He is especially disadvantaged because Barrayar is a planet that disdains imperfections, often aborting "inferior" fetuses. He is a great contrast to his noble father and his headstrong mother.

The Warrior's Apprentice advances the story of the "Vorkosiverse", introduces a significant new character, and stands alone as a good adventure story.