What happened in Agatha Christie's life and which of her books should I read first?

I love to learn about new and interesting things. Cars, animals, people of various stature, I don't care, I just love to learn. So, recently I heard about a world re noun author, Agatha Christie and I read that she was knighted Dame Agatha Christie. I love murder mysteries and that's what shes famous for so if you could, please give me a little insight on Agatha Christie's life, significant events and suggestion to which book of hers I should read first, I would be grateful. :) Thanks!