Shel Silverstein was something of a maverick in the field of children’s literature. Publishers were hesitant to touch The Giving Tree, a book now considered a classic of the genre, because of its sad ending and mature themes. Fortunately for us, Silverstein persisted. Today, six years after his death in 1999, fans can explore Silverstein’s imagination through a comprehensive Web site devoted to his work, life and music. It’s a fun ride for adults as well as children, peppered with music, sound bites and animation. There’s so much material, in fact, that the Web site is akin to a cyber-exhibition on the artist-musician’s life and work. Get to where the sidewalk ends, and if you don’t like it, you can call me “Sue.”