Being a young adult series this is a fairly quick read and really great for immersing yourself. The series consists of three quartets, Song of the Lioness, The Immortals, and The Protector of the Small. There are also a few books that follow or precede these quartets, but these three are the original ones I read. All the quartets follow strong (but not without weakness) female characters trying to be true to themselves in a fantastic world full of challenges.
This series is young adult, however, and does deal with some subjects like fighting and killing, female menstruation and other women's issues, and a small amount of sex. This is not a graphic series though and all these subjects are mentioned very tastefully and in keeping with the storyline. I think it is a fantastic series for a preteen or teen to read because it is really relatable for someone who is dealing with growing up.
Tamora Pierce Books