WORTH NOTING ON TV

* SATURDAY

New Yankee Workshop (PBS, 2-2:30 p.m.): Get ready for spring with this how-to on building a backyard garden shed with an adjoining area for materials set aside for recycling. Featuring master carpenter Norm Abram, this special show concludes March 23.

* SUNDAY

The Show (FOX, 8:30- 9 p.m.): Two venturesome comedies debut on FOX tonight, starting with this one from John Bowman and Matt Wickline (''Martin,'' ''In Living Color''). Taking aim at racial issues, ''The Show'' is set at a variety show, where the black host and crew learn that their new head writer is white.

Following a half-hour later is Local Heroes (FOX, 9:30-10 p.m.), about four twenty-something guys who aren't quite ready to relinquish their high school ways. Led by Ken Hudson Campbell, who also appears in the current movie ''Down Periscope,'' the comedy offers some well-scripted, original laughs. Some viewers may object to sexual innuendos and other risque material.

National Geographic Explorer (TBS, 9-11 p.m.): In the South African wilderness, two neighboring animals couldn't be more different: One is a sleek leopard, the other a rough-looking warthog. Yet both are raising broods. This special, entitled ''Beauty and the Beasts: a Leopard's Story,'' follows the two families for two years as each mother guides her young toward independence.

* MONDAY

South Bank Show (Bravo, 10-10:55 p.m.): ''I always had the idea that I would love to be a musician,'' says singer-songwriter Sting in this profile of his pop-music career. ''That was - and still is - my only ambition ... to make a living playing music.'' In addition to sharing his thoughtful, sometimes humorous outlook on life, the former member of The Police discusses his involvement in causes such as the Brazilian rain forest. The show was filmed mostly on Sting's British estate as he worked on ''Mercury Falling,'' his sixth solo album, which was released this week.

Please check local listings for these programs.