Republic Commando 1-3

The Republic Commando series (parts 1-3) by Karen Traviss
Originally commissioned as a tie-in to the Republic Commando video game, author Karen Traviss's writing was so highly praised its vivid characters and realistic treatment of military life that the story was continued in a popular series. The story follows the life of several clonetrooper commandos during the Clone Wars, delving deeply into their identity as cloned soldiers, as well as their sometimes lackluster relationships with the Jedi and others. Packed with lots of military action.

Buy on Amazon:
Book 1: Hard Contact
Book 2: Triple Zero
Book 3: True Colors

Story continued in Order 66: A Republic Commando Novel.

This is a prequel era series from the Legends timeline. It may be contradicted by newer books, movies, or TV shows (if so, just think of it as an alternate universe).