This is the link where the number of U.S. casualties in Iraq (admitted to by the U.S. government) may be researched.
These are the totals of U.S. soldiers who have died in Iraq that I managed to locate on the pentagon's website:
March 2003 - 54
April 2003 - 93
May 2003 - 32
June 2003 - 24
July 2003 (through 7/10) - 10
Total - 213
Total since the end of "major operations" on May 1 - 66
Things to note about these numbers:
The Department of Defense is extremely slow in releasing names of dead U.S. soldiers - some of these releases, especially for March and April, were not posted until recently.
There is no real distinction between "combat" and "non-combat" deaths, because all of Iraq is the theatre of war.
Reporting only "combat" deaths gives the impression that fewer U.S. soldiers died in Iraq when in fact the number of dead U.S. soldiers is at least 213.
The postings for June have changed several times. At one point the press releases were completely removed from the DoD site.
Since the public reacts so poorly to new of war casualties (they don't want to be involved in another Vietnam) there is an incentive for the DoD to underreport or to be slow to report the number of dead U.S. soldiers.