Pausing a macro repeatedly for data entry

Sub COLUMN_C()
'
' COLUMN_C Macro
'
' Keyboard Shortcut: Ctrl+Shift+C
'
ActiveCell.FormulaR1C1 = "P"
ActiveCell.Offset(0, 3).Range("A1").Select
ActiveCell.FormulaR1C1 = "25"
ActiveCell.Offset(0, 2).Range("A1").Select
ActiveCell.FormulaR1C1 = "2"
ActiveCell.Offset(1, -5).Range("A1").Select
End Sub

I need this macro to pause for "data" and take me to the next cell down so I can start all over again and hopefully loop 'COLUMN_C' so I can start from, say, C8 and just keep going down the column until the job's done or my fingers grow numb. Love Excel but know very little about editing macros and making them work harder!

I looked at several online suggestions and could not understand any of them. It's a simple macro doing a very important job and I'm hoping that an expert can show me how to put pauses in place of "P" and "25" and "2" and speed up the work I am doing which right now is rewarding but tedious.

This code

Sub selectCells()
    Dim r As Long
    Dim c As Long
    Do
        r = ActiveCell.Row
        c = ActiveCell.Column
        Call waitForInput(ActiveCell.Address)
        If Cells(r, c).Value = "stop" Then Exit Sub
        Cells(r, c + 3).Select
        Call waitForInput(ActiveCell.Address)
        Cells(r, c + 5).Select
        Call waitForInput(ActiveCell.Address)
        Cells(r + 1, c).Select
    Loop
End Sub

Sub waitForInput(start As String)
    Do While ActiveCell.Address = start
        DoEvents
    Loop
End Sub

will

1. wait until you enter something in the active cell
2. wait again until you enter something in the cell 3 cells to the right of that
3. wait again until you enter something in the cell 2 cells to the right of that

It will then move to the next row (immediately under the originally active cell of the previous row) and repeat the process (unless you enter stop in that first cell).