A breezy, anecdotal insider's memoir of network television, from a top producer (""The Mary Tyler Moore Show"") who also chaired NBC for five years in the early 1980s. Aided by former NBC executive Rukeyser, Tinker spins stories from 40 years in a colloquial, irreverent voice; he admits most of his important decisions were made haphazardly. In 1949, after failing to find a job in publishing, he joined NBC Radio, developing quiz shows, then crossing over to the network's fledgling TV section. After leaving for a stint in advertising, he returned to NBC's California division in time to further his relationship with Mary Tyler Moore of ""The Dick Van Dyke Show,"" who became his second wife. Eventually, Tinker decided to form a production company -- MTM -- when his wife was offered her own show. Tinker affectionately recalls the talents and trials involved in building unorthodox shows like ""Hill Street Blues,"" where network anxieties had to be assuaged, and ""Lou Grant,"" which lost sponsors in response to star Ed Asner's vocal leftist politics. Tinker's years at NBC were rewarding, but he laments the network's takeover by General Electric, with ""it's just another business"" approach. Tinker imparts some lessons learned along the way. Programmers should follow their instincts and recognize that new series, especially innovative ones, need time to find an audience. Flagship news programs represent the network at its best, so the current belt-tightening bodes ill for quality. Tinker takes pride in having booted shock-jock Howard Stern from NBC radio. But the high standards and public service approach he calls for will rely more on networks' noblesse oblige than on policy proposals. He also predicts, contrary to the view of many media observers, that some networks will continue to thrive in the expanding universe of cable. A late-summer beach read for TV folk and curious couch potatoes.