#1 The Magician's Nephew
This book was published midway through the series, but because it tells the story of how Narnia came to be, I decided to read it first this time. Digory and his friend Polly, using his uncle's magic rings, take themselves to a decaying world where they inadvertently wake up the evil Queen Jadis from her long sleep. They try to get home using the rings again, but find themselves in another world, one just becoming Narnia where we meet Aslan for the first time. Jadis becomes The White Witch of Narnia in later books, and Digory becomes the elderly professor of The Lion, The Witch and The Wardrobe.
#2 The Lion, The Witch and The Wardrobe
Peter, Susan, Edmund and Lucy, like many other English children during WWII, are sent to live in the country when London is bombed. Their host, an elderly professor now, is Digory from Book #1. Lucy is the first to discover that an old wardrobe in an otherwise empty room is a passageway to the land of Narnia, but the others won't believe her when she tells them of her adventure there. Edmund follows her the next time and he meets the White Witch, the one responsible for Narnia being "always winter, never Christmas" who bribes him to bring his siblings to her. When the other children back on our world are looking for a place to hide from the housekeeper and guests, they hide themselves in that same wardrobe. It is full of coats but pushing toward the back Peter and Susan are surprised to find the coats are behind them and they are walking through trees in snow.
They meet Aslan the Lion, the creator of Narnia, who is going to fight the witch and restore Narnia to the beautiful, peaceful world it is meant to be. But unknown to the children, things are going to get (or appear to get) much worse before they get better.
#3 The Horse and His Boy
Shasta lives with the old fisherman he calls father until a Tarkaan arrives and demands to purchase him for a servant. The Tarkaan's horse, Bree, a talking horse from the land of Narnia and also a captive, suggests they run away together and so they set out for Narnia.
Soon they meet a young girl, Aravis, who is running away from a marriage, arranged by her hateful stepmother, to a much older, evil man. Accompanying her is her horse, Hwin, whom they soon discover is, like Bree, a talking horse from Narnia.
Their journey is full of adventures and danger, and some surprises. Shasta learns he's not the fisherman's son, but rather the son of King Lune of Archenland and twin brother to a young prince.
Although Shasta and Aravis are the central figures in this story, Aslan the Lion and the four children from the previous book, Peter, Susan, Edmund, and Lucy, now royalty in Narnia, appear throughout this book, tying it in with the larger story.
#4 Prince Caspian: The Return to Narnia
Peter, Susan, Edmund, and Lucy are on their way back to boarding school after the holidays when they are suddenly pulled out of their world and back into Narnia, where their help is needed to fight the evil King, Miraz.
The King's nephew, Prince Caspian, was meant to inherit the throne, but Miraz now wants his own infant son to follow him as King and so he must get rid of the Prince. Caspian makes his escape and soon finds himself in a land of talking animals, with the King and his armies fast bearing down on them.
When the four children arrive and are recognized as the Kings and Queens they are in Narnia, they take council with the animals and realize there is no way to avoid war with the King. They prepare to fight, knowing that unless Aslan himself comes to help, they could very well lose this battle.
#5 The Voyage of the Dawn Treader
Edmund and Lucy are at their Aunt and Uncle's for the summer when they and their rather nasty cousin, Eustace, are pulled into a painting of a boat on open water. They find themselves, dripping wet, aboard the Dawn Treader with Prince Caspian and his crew on a quest to find seven missing Narnians. The seven had set out to find the End of the World and had never been heard from again.
Their adventures include: being taken prisoner in The Lone Islands, Eustace becoming a dragon (after which experience he becomes a less-nasty boy), fighting off a Sea Serpent, finding a lake that turns whatever touches it to gold, a visit to the Island of Voices where the inhabitants are under an invisibility spell that only Lucy can reverse, and stopping at an island called "The World's End".
Beyond that there is only "The End of the World". Ship and crew set sail to find it and when they do, Aslan meets them and sends Edmund, Lucy, and Eustace home where they find themselves back in the room with the painting that started it all.
The journey is successful in that they are able to account for all seven of the missing Narnians though not all of them have survived. It ends on a wistful note as Aslan gives the children some news they are sad to hear.
#6 The Silver Chair
Jill and Eustace leave school and visit Narnia, where Aslan gives them an assignment. They are to find Prince Caspian's son, Rilian, who 10 years ago left to seek vengence on his mother's murderer and never came back. Aslan gives them four signs to obey but Jill forgets three of them, causing all sorts of trouble.
They meet a giant owl called Master Glimfellow and attend a Parliament of Owls. A marsh-wiggle named Puddleglum becomes their guide as they set out on their quest. Arriving in the Ruined City tired and hungry, giants tell them about Harfang and encourage them to go there for the Autumn Feast. When they finally reach that city they are warmly welcomed by the evil Queen who intends to serve them up as a tasty dish at said feast.
In the end they escape all the dangers and Prince Rilian is re-united with his father, King Caspian, now a very old man. Jill and Eustace find themselves back at school, but not before a very special stopover in Aslan's country.
#7 The Last Battle
As Naria's days are winding down, an ape (Shift) and a donkey (Puzzle) find a lion's skin that Shift insists Puzzle wear. Shift will tell everyone that Puzzle is Aslan and Shift is his spokesman, telling the people what Aslan now requires of them.
Meanwhile Tirian, the last king of Narnia, learns of the trouble and sets out with his unicorn friend, Jewel, to set things right. Captured and in need of help, Aslan sends Jill and Eustace to his aid. Fierce battles are fought, but just when it seems all is lost they are rescued by the sudden appearance of seven Kings and Queens. Among them are King Peter, Queen Lucy, King Edmund, Lord Digory, Lady Polly and other characters from the previous books.
Though sad to see Naria come to an end, they are overjoyed to find themselves in Aslan's country with all the old compaions they'd thought were lost to them forever. Here, reunited with their parents, they find that what they thought was the end is only the beginning of the best possible happily-ever-after there could be.