Two categories completed, and I think it's a total of 44 books - counting them in more than one category makes it hard to keep track, especially when I don't properly tag the books in LibraryThing.
Overall:
Shakespeare-related (20%)
Poetry (10%)
Biography (30%)
Contemporary YA (100%)
Children's non-fiction (60%)
Science fiction (20%)
History (100%)
Mystery (60%)
Written before 1900 (40%)
Pulitzer winners (40%)
1. Shakespeare-related (2/10)
Shakespeare: The World As a Stage, Bill Bryson
Contested Will: Who Wrote Shakespeare?, James Shapiro
2. Poetry (1/10)
Red Bird, Mary Oliver
3. Biography (3/10)
Shakespeare: The World As a Stage, Bill Bryson
The Hiding Place, Corrie ten Boom
Beatrix Potter: Artist, Storyteller, and Countrywoman, Judy Taylor
4. Contemporary young adult (10/10)
Sweet, Hereafter, Angela Johnson
A Wish After Midnight, Zetta Elliott
The Clearing, Heather Davis
The Things a Brother Knows, Dana Reinhardt
The Six Rules of Maybe, Deb Caletti
Extraordinary, Nancy Werlin
Kissing Tennessee, Kathi Appelt
My Most Excellent Year, Steve Kluger
Habibi, Naomi Shihab Nye
Only the Good Spy Young, Ally Carter
5. Children's non-fiction (6/10)
Honeybees: Letters From the Hive, Stephen Buchmann
The Boys' War, Jim Murphy
How Do You Go to the Bathroom in Space?, William Pogue
Bloody Scotland, Terry Deary
Math Doesn't Suck, Danica McKellar
The War to End All Wars, Russell Freedman
6. Science fiction (2/10)
Twenty Thousand Leagues Under the Sea, Jules Verne
Android Karenina, Leo Tolstoy and Ben Winters
7. History (10/10)
Unsettled: An Anthropology of the Jews, Melvin Konner
The Boys' War, Jim Murphy
The Imperial Cruise, James Bradley
Blood and Thunder, Hampton Sides
Playing the Enemy, John Carlin
The Guns of August, Barbara Tuchman
Helluva Town, Richard Goldstein
Hellhound on his Trail, Hampton Sides
A Nation Rising, Kenneth C. Davis
Farmers Against the Crown, Keith Jones
8. Mystery (6/10)
Poirot Investigates, Agatha Christie
The Seven Dials Mystery, Agatha Christie
The Mapping of Love and Death, Jacqueline Winspear
The Weed That Strings the Hangman's Bag, Alan Bradley
A River in the Sky, Elizabeth Peters
The God of the Hive, Laurie R. King
Dark Road to Darjeeling, Deanna Raybourn
9. Written before 1900 (4/10)
Robinson Crusoe, Daniel Defoe
Twenty Thousand Leagues Under the Sea, Jules Verne
Roughing It, Mark Twain
The Adventures of Huckleberry Finn, Mark Twain
10. Pulitzer winners (4/10)
Among Schoolchildren, Tracy Kidder
The Guns of August, Barbara Tuchman
Red Bird, Mary Oliver
War in a Time of Peace, David Halberstam
