I enjoyed Bean Trees (though it's not what I'd call a must-read...) I accidentally read the sequel, Pigs in Heaven, first--luckily it didn't matter much. Try this book if you're in the mood for personable characters, interesting dialogue, and a good story.
Barbara Kingsolver is simply an exquisite writer. I liked, maybe even loved, her book The Poisonwood Bible (it's a heavy read, but worth the effort.) I couldn't resist sharing these great mothering quotes from Bean Trees.
"I'm just not up for the job [of being a parent]."
-"Well, don't feel like the Lone Ranger...Nobody is."
"When you told me that about babies getting dehydrated it scared the living daylights out of me. I realized I had no business just assuming I could take the responsibility for a child's life."
-"There's not a decent mother in the world who hasn't realized that."
"Nobody can protect a child from the world. That's why it's the wrong thing to ask, if you're really trying to make a decision."
-"So what's the right thing to ask?"
"Do I want to try? Do I think it would be interesting, maybe even enjoyable in the long run, to share my life with this kid and give her my best effort and maybe, when all's said and done, end up with a good friend."