The Sweetness at the Bottom of the Pie, Alan Bradley
I am hooked. The narrator is 11 year old Flavia de Luce, the youngest of 3 girls living with their widowed father. Flavia is an interesting cat enthralled with chemistry (which I LOVE! I absolutely adore chemistry) and particularly poison. When she stumbles upon a corpse in the cucumber patch outside her window early one morning, she determines that she will get to the bottom of it all.
Don't be fooled. She's not Nancy Drew. She is refreshing and intelligent, sometimes impertinent. I'm having fun coming up with my own conclusions and am anxious to find out if any of them are right or not!
Update: I loved the ending! Some of my hunches were in the right directions, and others couldn't be further from the truth. Oh, and I love the sibling rivalry subplot too. I found out there's a sequal!