Subtitled ``The Owl Internet Guide for Kids,'' this heavily illustrated book surveys the major parts of the Net, including e-mail and the World Wide Web, offering tidbits of history, anecdotes, vocabulary, safety tips, and more. It ends with a ``Yellow Pages'' directory of more than 250 suitable sites on the Web, divided into categories. Inset boxes, full-color photographs, mini-glossaries, cartoons, and diagrams fill every page. The humor is occasionally weak, the use of kid slang runs high (``cool stuff'' is the most overworked phrase of the book), and the constant use of the cyber- prefix is grating, but this guide displays a real grip on the information and is organized to make it fairly accessible to novices and more experienced users alike. The lively, appealing format compensates for too few screen shots, and that annotated directory of Web sites is particularly useful. (disk, not seen, glossary, index) (Nonfiction. 8-13)