Odd and the Frost Giants by Neil Gaiman

From chapters.ca:
In a village in ancient Norway lives a boy named Odd, and he's had some very bad luck: His father perished in a Viking expedition; a tree fell on and shattered his leg; the endless freezing winter is making villagers dangerously grumpy. Out in the forest Odd encounters a bear, a fox, and an eagle - three creatures with a strange story to tell. Now Odd is forced on a stranger journey than he had imagined - a journey to save Asgard, city of the gods, from the Frost Giants who have invaded it. It's going to take a very special kind of twelve- year- old boy to outwit the Frost Giants, restore peace to the city of gods, and end the long winter. Someone cheerful and infuriating and clever...Someone just like Odd.