IO9, which said that "Diane Duane's Young Wizards Is The Fantasy Book Series Everyone Should Be Reading." I don't know if I agree that everyone should read it, but I did and I liked it, and I'm pretty picky, so you probably should, too.
So You Want To Be A Wizard is the first book in the series, and it somehow hits every single step we expect of a book about a girl who gets to be a wizard, while somehow making the story still seem fresh and interesting. That's tough to do, especially since competing with Harry Potter in that department is kind of like writing a swords-and-sorcery adventure using elves and wizards without being accused of mimicking Tolkien -- and while still being original.
I should note that So You Want... actually precedes Harry by nearly two decades, so while I read Rowling's series first, if anyone copied anyone... forget that. J.K. Rowling is superlitigious, as is apparently every single person who ever read her book, according to this Wikipedia article on the number of people who sued her and lost badly.
So You Want To Be A Wizard has a misunderstood and bullied protagonist (Nita) who finds a magical book accidentally (the Wizard manual), learns that she is one of the rare few people who can be a wizard, and sets out on a quest that involves her saving the world... eventually. It has a fire-breathing dragon, it has a friend who is better at spells than Nita is who kind of shows her the ropes, it has trees coming to life and battling, and it features kids who really use about two or three spells to get everything done.
That said, the book doesn't really feel like it's full of tropes, at all, first because the writing is done pretty well: the book moves along at a good pace. I suspect it's aimed as a YA book but like the Potter and Narnia books it resembles (or which resemble it) it doesn't feel like it's meant for a 13-year-old.
In addition, Duane adds nice touches to her magic: the magic is a combination of the heavily-detailed magic that Lev Grossman uses in his Magician series and science. The magic here is largely used through Speech, which is a way of describing the world that helps keep things alive and which also can change things: wizards work in part by simply talking in magical language that convinces things to be other things, so Nita can change a stone wall into a door by convincing it that it's a door. That's a neat concept that I wish I had thought up.
Duane also gives a reason for magic and magicians to exist: They keep the universe from running out. The mythos behind the series has to do with a master of evil, who goes by a lot of names but mostly is referred to as You-Know-Who, because nobody can say his name.
AS AN ASIDE I think we can stop that now: The Villain Whose Name Can't Be Said Because He Will Hear And Destroy You is dumb. I never liked the concept, and it hasn't grown any better with repetition. JUST SAY THE VILLAIN'S NAME.
Anyway, this Master of Evil at the dawn of creation got scared and introduced entropy, and thus death, to the universe, meaning that one day the Universe will end. So wizards have the Speech, which they can use to keep things alive, and the main collection of the Speech is found in The Book Of Night With Moon, which honestly is an awesome name and is another example of how Duane's book rises above average-level Magical Kid fiction. Periodically, wizards have to get The Book of Night With Moon and read from it to keep the universe from ending, and that's [SPOILER ALERT THAT YOU'D PROBABLY HAVE SEEN COMING IF YOU GAVE A MOMENT OR TWO'S THOUGHT ABOUT THIS BEING THE FIRST BOOK IN THE SERIES] what Nita and her young wizard friend Kit have to do: They try to practice their first spell to find a special pen a bully stole from Nita, and in doing so accidentally call into their world a sentient white dwarf star they call "Fred" who teleports the pen to the monstrous version of New York where You Know Who lives, and where it turns out the Book of Night With Moon happens to have been hidden.
The white dwarf star thing is an especially nice touch: Fred is one of the better characters I've come across in any book, and again is one I wish I'd thought of. It's stuff like that, and the monsters in Alternate New York, and the fact that the whole book feels super-well-thought-out, that makes this book worth reading.
So, not maybe for everyone. In terms of 'kids discovering they would save the world' books, it's nowhere near as good as the Narnia books or His Dark Materials, but it's at least equal to Harry Potter or those Prydain books.