The writing staff of Syfy's EUREKA has a blog with a lot of behind the scenes info: http://eurekaunscripted.
Soon they'll also be posting a Day in the Life of a Showrunners' Assistant/Office PA, and various production positions. You can also follow the EUREKA writers on Twitter. Thanks to Kira for the info!
Margaux Froley has started a new blog called This is Your Pilot Speaking. (Ha! I just got it. It's early.) She last wrote on CW's PRIVILEGED, so she knows what she's talking about.