congrats! as an elementary teacher i can tell you that storytellers are so important in children's lives. it helps promote literacy, imagination and gives children a voice when maybe they are too shy to speak. i did read aloud every day in my classroom and it was their favorite part of the day!
My son is 3 and loves: The Gruffalo, Gruffalo's Child, Chicka Chicka Boom Boom, Knuffle Bunny, Eric Carle books, Dr. Seuss, Tomie DePaolo books, all Kevin Henkes books, Pocketful of Kisses,
My students who were 6,7,8 yrs old loved: same as my 3 year old, Cynthia Rylant books, William Steig books, Cloudy w/a chance of meatballs, Click Clack Moo, and chapter books like Junie B. Jones, SPongebob Square Pants, Marvin Redpost. As a story teller you can also read harder chapter books that might be appropriate for age 12 like the Beverly Cleary books (Ramona, Freckle Juice etc...), Roald Dahl books (James and the Giant Peach etc...), Because of Winn Dixie.
Hope this helps!