Working with multiple sheets

Hello, I am new to this forum and to excel. I am using excel 2007. I am trying to create a time management worksheet that will help me keep track of my clients and the hours I bill throughout the month. I am using multiple sheets to track my daily, weekly, and monthly totals. I have figured out how to make calculations by linking them to different sheets to get my totals for my weekly and monthly sheets. My problem is I want to make sure that on my column I have named "Client" that when I enter a name into it the rest of the sheets display that name in its corresponding cell i.e, if Sheet 1 A5 is "John" I would like Sheet 2 A5 to display "John" and Sheet 3 to display "John" etc. I do not want to have to enter "John" in each sheet, not that I am lazy, but I am afraid I will enter the name in the wrong row and thus messing up my whole billing. That way the name of my clients are uniform throughout each sheet. If that makes sense to anyone please advise or if you have other suggestions on how to create this type of database let me know. My upfront thanks to anyone who can help.