Billed as a travel guide for movie buffs, Roadside Hollywood: The Movie Lover's State-by-state Guide to Film Locations, Celebrity Hangouts, and More, the exhaustive compendium of trivia is the stay-at-home's companion to Hollywood Babylon, Kenneth Anger's encyclopedic study of Tinseltown gossip. For example, ''Kansas' Gifts to Hollywood'' includes the settings for Picnic, Carnival of Souls, In Cold Blood, Bad Company, Prime Cut, Paper Moon, The Day After. If that's what you need, here it is. B