This guide is designed to alert readers to the scope and variety of programming coming up. Listing is not meant to represent blanket endorsement. Viewers are urged to be selective. FRIDAY Leg Work (CBS, 9-10 p.m.): Premi`ere of new crime-drama series starring Margaret Colin (``Foley Square'') as former DA/private eye. 20/20 (ABC, 10-11 p.m.): Barbara Walters profiles and interviews Mikhail Baryshnikov. Camp David (PBS, 10-11 p.m.): Behind-the-scenes look at the famous presidential hideaway. SATURDAY The Experiment (PBS, 7-7:30 p.m.): Third episode of 13-part ``Degrassi Junior High'' series about topics of significance to teens. 1919-1928: The Call of Faraway Places (PBS, 9-11 p.m.): Premi`ere of eight-part, 16-hour German series titled ``Heimat,'' chronicling life in a fictitious village from 1919 to 1982. Subtitled in English.
SUNDAY Spirits of the Forest (PBS, 8-9 p.m.): ``Nature'' explores Madagascar, off the east coast of Africa, where flora and fauna have evolved in total isolation for millions of years. The Struggling People (PBS, 10-10:30 p.m.): Part 4 of ``Only One Earth'' series concentrates on population control in Africa. Made in China (PBS, 10:30-11 p.m.): Premi`ere of three-part ``Silk Screen'' series exploring the American dream through the eyes of immigrants.
MONDAY The Workplace (PBS, 8-9 p.m.): Second program in five-part series, ``America by Design,'' with architectural historian Spiro Kostof. God Bless Standard Oil (PBS, 9-10 p.m.): Premi`ere of eight-part series documenting how oil has influenced the course of world events.
TUESDAY Death of a Star (PBS, 8-9 p.m.): ``Nova'' tracks the recent discovery of an exploding star in a nearby galaxy. Law and Order (PBS, 9-10 p.m.): Third part of superb four-part documentary series, ``We the People,'' hosted by Peter Jennings. An English-Speaking World (PBS, 10-11 p.m.): Premi`ere of repeat of Robert MacNeil's superb series ``The Story of English.''
WEDNESDAY Discover: The World of Science (PBS, 8-9 p.m.): Season premi`ere of fine science magazine show has fascinating segment on manatees in Florida. Corridos! Tales of Passion and Revolution (PBS, 9-10 p.m.): Theatrical presentation of traditional Mexican-American folk ballads by Linda Ronstadt, Daniel Valdez, Evelyn Cisneros, and Clancy Brown. Together to Mars? (PBS, 10-11 p.m.): Documentary raises the question of whether exploration of Mars will involve Russian and American cooperation. Listings are in Eastern time; other zones may vary. Please check listings for all PBS programs, since local option often results in differing days and times.