Black Friday 2009 (November 27th) is 6 weeks away, but if last year is any indication retailers will start Black Friday flavored deals already November 1st.
In 2008 Kmart launched their early Black Friday sales already on Sunday November 2nd. Other retailers followed that lead and started their Black Friday sales earlier than the year before. Most retailers take now at least the whole Thanksgiving week to offer new Black Friday deals every day.
For instance Amazon had in 2008 a Black Friday Countdown - offering a new deal each day leading up to Black Friday.

The deals do not stop on Black Friday though as they spike again on Cyber Monday and most retailers try to somehow keep up the sales momentum with new deals after Monday as well.

This year we might even see more early Black Friday sales than last year. It gets harder for consumers to predict the best time to buy as it could be that a deal is better early November than on Black Friday itself. Update 10/29/09: It has begun. Sears announced Black Friday Now Promotion starting on Halloween.

The most anticipated Black Friday deals from the big retailers will be revealed in Mid-November. Walmart is expected to release their Black Friday deals on or around November 23rd.

We will do our best to help you through this Black Friday and Thanksgiving deal flood in our Black Friday 2009 Coverage.