You should know I would not do this without a John Irving novel in the mix. And if you're going with one, you should probably go with the one he adapted into a screenplay and won an Oscar for. That's just common sense.
Since the author adapted it, the plot of book and movie are pretty much the same. In the early 20th Century up in Tony Laplume's backyard of Maine there's an orphanage run by a Dr. Wilbur Larch. Since this is long before Roe v. Wade, he gives illegal abortions to women who stop at the orphanage. But of course some women just leave a live kid there. One of those is Homer Wells, who is adopted a few times, but it never worked out so he became the doctor's apprentice.
Then a wealthy guy and the hot lobster farmer's daughter he knocked up show up. The girl, named Candy, gets an abortion and Homer is smitten with her. He goes with her and her boyfriend Wally to an apple orchard, where he works picking apples with a bunch of black migrant workers.
Where the movie and book diverge is that in the book there's a 15-year jump from World War II to the 50s. By then Candy has given birth to Angel, a boy fathered by Homer. Angel falls in love with a migrant worker named Rose Rose, but she has gotten knocked up by her dad and so Angel gets his dad's help performing an abortion. Yay?
The movie doesn't have that jump, which is just as well because it would make the movie like 3 hours long and the son thing didn't really matter all that much in the scheme of things. It's pared down so that it all happens within a year and Homer doesn't fall in love with Rose Rose but is moved by her plight enough to help her.
Of course there are a lot of people who won't read the book or watch the movie because of the abortion issue. What I like best is instead of shouting about God or shrieking, "My body, my choice" or any other slogans you might see on picket signs, it takes the pragmatic view that outlawing abortion forces women to make impossible and desperate choices that often lead to mother and fetus dying. The book is more graphic about this than the movie. In the book a woman takes some potion that basically liquefies her insides. The other side of the coin is what happens to the orphans from those fetuses who don't get aborted. The book goes a lot more into the life of Melony, a girl who like Homer never really found a home. She's seen a few times in the movie but in the book she's a big, bossy girl who goes to a city to work in an aircraft factory during WWII and becomes a lesbian. There's also Fuzzy Stone, a sick kid who eventually dies. So really you see the human cost that makes it a lot less black-and-white than bumper stickers make it sound.
The movie is not quite as effective as the book if only because a lot had to be cut out for a manageable running time. But the movie is a lot less dense for the more casual reader who doesn't want to wade through more than 500 pages.
There you go. I could have also done The Hotel New Hampshire, The World According to Garp, A Widow for One Year/The Door in the Floor, and A Prayer for Owen Meany/Simon Birch but I didn't. Too bad none of them started with a K or X.