The Shadow Children series by Margaret Peterson Haddix starts with the story of Luke Garner in Among the Hidden and follows him loosely through six additional books. (Several books follow another child, but the main plot revolves around Luke.)
It's your standard distopia of a future in which droughts and alleged famines led to a population law limiting families to two children. It's not a particularly new idea. They have it in China. It's a backdrop to Ender's Game. But the stories of these children still feel important. They have real problems and fears. And their actions - and consequences - have a real feel to them too. None of the 'spy kids' drama where adults are stupid and kids can do fantastic things. The adults in this series are intelligent and compassionate while at the same time, they are limited and have their own fears. The children are brave and inventive, but I never question that a child could do what they do.
The books are young adult literature. They're fairly short, and they're quick reads. I finished each of them in about a day. I recommend.