From the first page of this launch title of a beginning readers series, the audience will feel like they're enrolled in Ms. Star's class, deciding what to make for the science fair along with adorable Pearl (a rabbit) and her friend Wagner (a mouse). Alley's (Mrs. Brown on Exhibit) illustrations enhance this effect with their knee-level or just-at-the-next-desk perspectives. McMullan (I Stink!) moves the story forward with simple, authentic dialogue. "I'm going to make a robot," says Pearl while Wagner dreams, "I am going to win a prize." Streamlined vocabulary and sentence structure accommodate the needs of newly independent readers without constricting the story. The last chapter segues to a believable tiff (Wagner hurts Pearl's feelings when he tells her that her new green boots "look like big fat pickles and... make way too much noise"). Alley's detailed watercolors divide the text in a variety of attractive layouts and add extra charm and emotion to the proceedings. Budding readers will want to follow this duo's further adventures. Ages 5-8. (Sept.)