Nobody still seems to have solid figures on Najaf. An estimate on http://www.empirenotes.org/august04.html (from early last month puts total deaths at 600 to 1000.

From the Aug. 27 New York Times:

As many as 1,000 guerrillas may have been killed since early August, American commanders say, along with 11 American marines and soldiers. More than 100 have been wounded, including dozens of serious injuries.

The two sides have caused uncounted civilian casualties and inflicted tremendous damage on Najaf's Old City. The area stinks of sewage and soot, and its streets are filled with rubble from bombed-out buildings. Even the mosque has been slightly damaged.

I realize the article includes no specific figures for civilians.

I checked Al-Jazeera, BBC other sources--no figures.