What I mean is: when you look at the main sheet, how do you know which data
cells go with which program?  For instance, is the program name listed down
Column A, and the data for that program is in H of the same row?  How many
cells need to be updated from the main sheet, and how do you know which ones
they are?

The biggest thing to remember about any routine like this is that it can
almost always be broken into smaller increments.  When you take it one step
at a time, it's not so very intimidating.  You do have to be able to
identify the process you would use without a macro, because your macro is
going to have to do that same process. And what we know intuitively when we
look at our work has to be spelled out in detail for in the code.

Try this:
-- Create a new Excel workbook and give it some more worksheets.
-- Put the macro below into a module.  (With Excel open, press ALT+F11 -
this opens the Visual Basic Editor (VBE).  Go to Insert >> Module.  Copy
everything below from "Sub UpdateAllSheets()" to "End Sub".)
-- Back in Excel, press ALT+F8 to bring up a list of macros.  Choose
"UpdateAllSheets" and see what happens.  (The macro sets the Zoom percentage
for every sheet except Sheet1.)
-- Go back to the VBE and look at the code, and see if you can understand
what the code is doing.

Ed

Sub UpdateAllSheets()

Dim objWkbk As Workbook
Dim objWksh As Worksheet
Dim strZm As String
Dim intZm As Integer

Set objWkbk = ActiveWorkbook

strZm = InputBox("What zoom?")
If strZm = "" Then GoTo ExitHere

intZm = strZm

For Each objWksh In objWkbk.Sheets
 If objWksh.Name <> "Sheet1" Then
   objWksh.Activate
   ActiveWindow.Zoom = intZm
   objWksh.Range("A1").Select
 End If
Next objWksh

objWkbk.Sheets("Sheet1").Activate

ExitHere:
End Sub