Warn graduated from Annie Wright School in Tacoma, WA in 1992. She then attended Wellesley College in 1996 with a degree in women's studies, and received a master's degree in theological studies from Harvard University in 1998. She spent eight years in online marketing before selling her gay and lesbian entertainment websites AfterEllen.com and AfterElton.com to Logo in 2006. Warn is currently an executive producer at Logo. Warn stepped down as the Editor in Chief of AfterEllen.com, with Karman Kregloe stepping into the role in 2009.
Warn's extensive written work on lesbian and bisexual women in entertainment has been included or cited in numerous magazines, including Velvetpark, Curve and Lesbian News; in newspapers like USA Today, LA Times, and Emmy Magazine; and in books like BITCHfest: Ten Years of Cultural Criticism from the Pages of Bitch Magazine, Queer Popular Culture: Literature, Media, Film, and Television, Bisexual Women: Friendship & Social Organization, and News and Sexuality: Media Portraits of Diversity. Warn also wrote the introduction to the Reading the 'L' Word, a collection of essays by academics and journalists about the Showtime drama The L Word.
In November 2006, Warn was honored as one of the year's "10 Amazing Gay Women in Showbiz" by non-profit organization Power Up. In December 2006, she appeared on a panel with other notable LGBT actors and activists on Logo's Queer Year 2006 TV special. She was one of four co-hosts on the first season of the online lesbian talk show She Said What?.
- "All hail the pioneer, Sarah Warn", LesbiaNation.com, 9 March 2007.
- "Erosion Media Execs"
- "MTVN's Logo Acquires Three LGBT Sites", paidContent.org, 8 June 2006.
- "365gay Joins Logo", 365gay.com, 8 June 2006
- "TV’s Top 10 “Lesbian” Crime-Fighter Shows" Curve Magazine
- "It's In to be Out These Days", USAtoday.com, 1 June 2003
- "Books on Amazon.com that reference articles by Sarah Warn"
- "Reading the L Word", 30 March 2006.
- "10 Amazing Gay Women in Hollywood in 2006", Planetout.com, 2006.
- 2006: The Queer Year, Logoonline.com December 2006.
- "A Show of Their Own" SouthernVoice.com, 26 January 2006
- "She Made Me Watch This!"
- "Who Thought THAT Was A Good Idea?"
- "One Word for 'L' Word: Logo" The Hollywood Reporter, 21 September 2007