If you don't know Brother Jeff, you don't know the heartbeat of Five Points, where Jeff Fard serves as switchboard, business booster and opinion-maker for the Black community at large. The new Black Dollar Saturday is perhaps his most grassroots initiative: He opens his Welton Street cultural center to Black entrepreneurs, artists, cooks and makers every Saturday from 11 a.m. to 5 p.m. in the spirit of Ujamaa, Kwanzaa's principle of Cooperative Economics. Come down and spend a dollar on soy candles, pencil portraits, plates of soul food, pickles, vinyl albums, jewelry or whatever happens to be on the tables each week.