Choose a book that you already love, so your familiarity and excitement for the book will manifest in your voice.
Conduct a dry run by reading your chosen book aloud, by yourself. Try out a few different delivery options for each line, as an actor might do when practicing a script for the first time. Use this time to loosen the muscles around your mouth, which will help with annunciation. Consider creating specific voices for each character, for example, a sweet, high-pitched voice for a princess or a deep, commanding voice for a brave hero.
Make your reading time special with a few simple traditions. Prepare a snack, dim the lights, build a little reading tent out of blankets or cuddle under the bed covers with a flashlight.
Read the entire book, injecting expression and drama in the appropriate places. Lower and slow down your reading voice in moments of suspense or vulnerability; add a more upbeat tone to underscore exciting and surprising moments. Don't rush through the reading -- remember, your toddler is learning new words and is experiencing the story page by page, image by image.
Pause to describe and define any words you come across that may be new to your toddler. Keep a children's dictionary handy to help define words in terms he will understand.
Engage discussion about the book after you finish reading the story. Ask your toddler questions such as, "How did this story make you feel?" or "Who are the main characters of the story?"