And the answers are...

1. They waved their handkerchiefs until they turned the corner from New Dollar Street into Elm Street. Now they could no longer see the yellow house. Good-by, yellow house! Good-by!

The Moffats, by Eleanor Estes

2. That room was full to the brim of something beautiful, and Betsy knew what it was. Its name was Happiness.

Understood Betsy, by Dorothy Canfield Fisher

3. The other [thing] is that back in our own world everyone soon started saying how Eustace had improved, and how “You’d never know him for the same boy”: everyone except Aunt Alberta, who said he had become very commonplace and tiresome and it must have been the influence of those Pevensie children.

The Voyage of the Dawn Treader, by C.S. Lewis

4. None throws away the apple for the core.
But if thou shalt cast all away as vain,
I know not but ‘twill make me dream again.

Pilgrim's Progress, by John Bunyan (the poem that ends Book I)

5. The mouse hurried to his safe home.
He lit the fire,
he ate his supper,
and he finished reading his book.

Mouse Soup, by Arnold Lobel

6. And Montmorency, standing on his hind legs, before the window, peering out into the night, gave a short bark of decided concurrence with the toast.

Three Men in a Boat (not to mention the dog), by Jerome K. Jerome

7. To begin perfect happiness at the respective ages of twenty-six and eighteen, is to do pretty well; and professing myself moreover convinced, that the General’s unjust interference, so far from being really injurious to their felicity, was perhaps rather conducive to it, by improving their knowledge of each other, and adding strength to their attachment, I leave it to be settled by whomsoever it may concern, whether the tendency of this work be altogether to recommend parental tyranny,, or reward filial disobedience.

Northanger Abbey, by Jane Austen

8. If every one of them were written down, I suppose that even the whole world would not have room for the books that would be written.

The Gospel of John

9. I took her hand in mine, and we went out of the ruined place; and as the morning mists had risen long ago when I first left the forge, so the evening mists were rising now, and in all the broad expanse of tranquil light they showed to me, I saw no shadow of another parting from her. ALTERNATE ENDING I was very glad afterwards to have had the interview, for in her face and in her voice, and in her touch, she gave me the assurance that suffering had been stronger than XXX's teaching, and had given her a heart to understand what my heart used to be.

Great Expectations, by Charles Dickens (he couldn't decide on an ending)

10. And Rose drew him in, and set him in his chair, and put little Elanor upon his lap.
He drew a deep breath. 'Well, I'm back,' he said.

The Return of the King, by J.R.R. Tolkien