Help creating workbook with worksheets "linking" cells

I'm sure this is easy for everyone, but me.
I need to enter a salesman's sales with date, job name, job amount,
commission amount on one worksheet.
I need to enter commission payments made with date and amount on another
worksheet.
Objective is to have a third worksheet that will then show running list of
jobs sold and commissions paid with running totals.
Challenge: I need to set this up so it's "dummy proof" as much as possible
so that I can have someone (who does not have Excel experience) entering data
in the simplest way possible.
Thank you in advance!!!
Bonnie