Here are a list of online articles from sources, generally regarded as on the Left end of the political spectrum, that attack Bob Woodward's credibility:

Daily Kos, June 2, 2005, "Bob Woodward...ALL smoke and mirrors?"

Huffington Post, October 29, 2005, "'Embedded Crony': Bob Woodward Shows His True Colors

Village Voice, November 15, 2005, "Woodward Dis"

Salon, June 18, 1999, "Only the Shadow Knows"

Salon, July 1, 1996, "Bob Woodward, Stenographer to the Stars"

Truth Out, November 22, 2005, "Blowing the Whistle on Bob Woodward"

The Left Coaster, "Woodward Now Implicated In Plame Inquiry - Testified Yesterday To Grand Jury"