B.L.
LOL!!! My now-three year old was the same way... Here's what we did; hope they help:
1. We considered it rude for her to interrupt while WE are reading, and so we say, "You're being rude and interrupting. Reading time is over until you are reading to sit still and listen quietly." Then we calmly put the book down and walked away.
2. If SHE is the one reading, we sit still and listen quietly to her. She is given time to read by herself when I am nursing the new baby. She cannot read to me while I'm nursing, because the baby (5 months) is more interested in her than in nursing when she's around.
3. We bought some new books and put the "baby" books away. This way she was interested in hearing the new stories.
4. If she's turning pages, we say "Mommy can't read the words if you turn the pages so fast. It helps her to understand where the words are and where we are at with the words if we use our finger to follow along. It's still her priveledge to turn the pages, but not until we say "Okay, turn the page."
5. Me, the mom, I read to her before naps. Her dad reads to her before bed. It's a routine set in stone since she was tiny. If she's being antsy or rude, we leave the room until she's calmed down. As she's gotten older, she wants more reading, because she knows it postpones bedtime :)