Teach about plot with picture books. Since picture books are short, you will be able to teach about story arcs, development of the story.
Demonstrate rhyme and alliteration. Alliteration is the repetition of a sound at the beginning of a word; rhyme is the repetition of a sound at the end. For example, the title "Peter Pan" (by J.M. Barrie) is an alliteration because the initial sounds are the same, and the the title "Fox in Socks" (by Dr. Seuss) is a rhyme, despite the spelling difference, because the ending sounds are the same.
Expand vocabulary by reading picture books aloud. Often, if a word is unfamiliar it can be explained in the context of the story or the illustrations. The combination of the pictures and the story helps to bring unfamiliar words into familiar territory.
Teach about personification by reading picture books with older students. Personification is giving human traits to inanimate things, like trees swaying like dancers, or the wind singing. Have your students find personifications in the illustrations or text and point them out to you.