Ella Enchanted by Gail Carson Levine
Ella Enchanted is a Newberry award winning fantasy book. It is based off a certain fairytale, (I won't tell you which one) and is a sweet, charming book.
It does have magic, such as curses, blessings, and fairy-godmothers, but no more than your average fairytale. It is also slightly romantic, but not overblown.
It has a good plot, character development, and action. It is a funny, magically written tale that keeps you on your toes waiting to see what happens next. It is a fairly easy read, and paced just right, not too fast that you loose track and not too slow that you loose interest.
It has some good themes, like overcoming difficulties, love, repentance, and looking at other peoples perspectives before acting. The main character is rebellious, but only to a certain extent...
It is amazingly well written, in a light, humorous style, yet also allowing some serious tones in as well. It has a sequel, Ogre Enchanted, which is also quite good. I would also recommend Gail Carson Levine's other children/teen books, most of which are fairytale rewrites, twisted slightly to make them more interesting.
I would say about 10+, and about 90%. I hope this inspires you to read it (And pleaseeeee don't just watch the movie, it doesn't count!)