Passing Rushing Total
Player TDs TDs TDs TDs/game
Dan Marino 72 2 74 2.5
Kurt Warner 71 1 72 2.4
Aaron Rodgers 56 8 64 2.1
Charles Conerly 55 6 61 2.0
Joe Montana 50 5 55 1.8
Fran Tarkenton 48 7 55 1.8
Peyton Manning 52 2 54 1.8
Tom Brady 46 1 47 1.6
Ben Roethlisberger 42 4 46 1.5
Steve Young 35 11 46 1.5
Steve McNair 33 12 45 1.5
John Elway 37 2 39 1.3
Brett Favre 36 2 38 1.3
Warren Moon 27 1 28 0.9
Bart Starr 19 4 23 0.8
As we can see, Aaron Rodgers is in pretty rarified air, as one of only four quarterbacks (that I can find) in the history of the NFL who averaged over 2.0 touchdowns per game in their first 30 starts. I don't think it's a coincidence that the top two names on this list played in Florida and a dome, respectively, and neither was sacked as much as Rodgers, which only makes his accomplishment all the more remarkable.
Charlie Conerly's story may be the most amazing of all, however. With only 4 starts in his 12-game rookie season (1948), he threw 22 touchdown passes, still second only to Peyton Manning (who threw 26 TDs in 16 starts) on the all-time list for rookies!