TV highlights: 'The Unauthorized Beverly Hills, 90210 Story' airs on Lifetime

(All times Eastern.)"Live From New York!" (NBC at 8 p.m.) looks at the first 40 years of "Saturday Night Live," with interviews with writers, performers and comedians."The Unauthorized Beverly Hills, 90210 Story" (Lifetime at 8) gives a behind-the-scenes look at the first four seasons of the 1990s teen drama.