THE PRACTICAL GUIDE TO PRACTICALLY EVERYTHING: 1997 Edited by Peter Bernstein & Christopher Ma (Random House: 788 pp., $9.95 illustrated, paperback original). Bernstein and Ma have compiled an updated version of an 18th century almanac--one that contains useful information, rather than obscure facts. They explain how to program a VCR, offer a comprehensible introduction to home mortgage rates and reveal why some types of insurance coverage aren't worth buying. Interviews with various experts keep the text lively: Jacques Pepin describes how to create flavorful, low-fat desserts; former Surgeon General C. Everett Koop discusses what to look for in a doctor; diva Cecilia Bartoli lists 10 favorite operas that will appeal to novice listeners. The result is a reference book readers can use for day-to-day problems, rather than school reports.