Lewis, C.S.

The Chronicles of Narnia

A classic portal fantasy series that sees various members of the Pevensie family transported by an assortment of magical artefacts into the land of Narnia. The Lion, The Witch and the Wardrobe (arguably the second book, but the first published and a good starting point) sees four Pevensies transported through a wardrobe into a winter wonderland full of talking beasts and mythological creatures. These books might not have aged quite as well as other contempories, and there might be a bit too much religious allegory for some tastes, but they remain a great introduction to the fantasy genre.