R help - Aug 2008 - testing for differences in sums - how to?

If I want to test for a salesman effect on average sale, I model it as
"Sale ~
Salesman". But what if I want to test for a salesman effect on total sales?
How do I model that?

Given a significant salesman effect, how do I follow up with the equivalent of 
Tukey's HSD to determine who the (indistinguishly) top salesmen are?

If I add another factor, say "region" to the design, how do I then
model the
result?

Thanks,

jkh