Well, how very... brief and abrupt. Baum doesn't do much in the way of "denoument" does he? I mean, the climax could be the showdown with the Wicked Witch of the West, in which case we have a whole like fourth of the book or so of it slowly meandering and winding down, or you could consider it when she actually finds out how to go home/meets with Glinda/etc., in which case... uh, yeah. *boom* okay, happy ending, close the book.
That said, it's a sweet enough fairy tale, and probably very nice if you don't have much in the way of fantasy in general. But yeah, looking at it like an actual book, the pacing stinks. But oh well! It's still sweet, and a classic, and alladat.
Also: the *one* thing really that I remembered about the book version from reading it previously was the fact that it didn't end with the whole "it was all just a dream! And you were there! And you were there!" which met with my wholehearted approval, and still does. If it's going to be a fantasy, let it be a fantasy, and not an extended dream sequence. Yeesh. Although I would have approved of her keeping the silver slippers, to leave open the possibility of her having future adventures, and spark the imagination.
(And Aunt Em would break the bank buying mourning, after they already have to get/build a new farmhouse? Not to mention that if she's going to be in mourning you'd think she already would be. But that's nitpicking again. :p )
And I'm with prince_corwin in thinking she would have released the winged monkeys from their bondage, but at least Glinda gets to do it, and show she's a kind and thoughtful witch. So that's okay, then! (Although usually isn't the idea that one of the wishes has to be sacrificed for that? But oh well!)