Brotherband Chronicles Book 1 The Outcasts by John Flanagan
Hal, an outcast in his village, is a quiet and an intellectual. His people value strength and warrior traits. But every boy must go through Brotherband training. If he succeeds, he will have his place on a viking ship. If he fails, he will remain an outcast for the rest of his life, not even able to find work or a wife. When the boys are split into groups, their Brotherbands, no one wants Hal, or his only friend Stig. But there are a few others that don't fit in as well. They form their own band, the Herons, and fight for a place of honor in their village.
This is an amazing adventure story...you find yourself rooting for this group of misfits. I will definitely be recommending this to teen boys (and girls, if they are like me) and I eagerly await the next in the series!