Percy Jackson Series, Rick Riordan
Fantasy. The Percy Jackson series is a great read, teaching about the Greek gods and myth, but with a modern twist. It's a great way to introduce your kids to Greek myths, because they will actually enjoy reading it. The main plot for the series is the Greek gods are still aroundand they move to wherever the center of civilization is, which in this case is the USA. As it turns out, the main character Percy Jackson is Poseidon's son, and therefore inherits some of his powers. This causes trouble for him though, as monsters are constantly chasing him, and he gets little drop-ins from gods from time to time (very inconvenient). Then Zeus's lightning bolt is stolen, and Percy is blamed. Pretty bad luck if you ask me. Now Percy has to find Zeus's lightning bolt, with help of his faithful satyr (goat person) Grover and the help of his friend/enemy Annabeth, and get it back before the Summer Solstice, seven days from now.
You'll find yourself laughing through most of the book when you see how the ancient myths add up to modern day USA. For example, the gods headquarters switched from Mount Olympus to the Empire State Building (they like being on a higher level then all of us lowly humans).
They do say "oh my gods"(plural because they are multiple gods) during the course of the series, and some violence, but that's all that I can think of warning you about. 10+