By Karen Valby
Updated September 01, 2000 at 04:00 AM EDT

With doctors and pseudo-experts clogging best-seller charts, we seem to be in the midst of a self-help heyday. Jennifer McKnight-Trontz’s Yes You Can is a kitschy compilation of life-changing books and gadgets revisits the era when ”self-help beamed its best, most hopeful smile,” the 1920s to the 1970s. For every issue there was a solution, even ”Reduce Through Listening,” a record that melted away pounds. Despite the book’s retro allure, its intended audience remains a mystery: Camp-craving cynics will probably lose interest, and self-help devotees will despair at how much yesterday’s promises sound just like today’s. B-