Consider two cases as follows:
1- If you want to add as separate tab:
You can copy an entire sheet to another file.
right click on the first sheet tab name and select move or copy and select
the second file name (It should be open in order to see its name)

2- If you want to add to same sheet:
Use Data| Consolidate
For more info on Consolidate refer to:
http://support.microsoft.com/default.aspx/kb/214270

If it helps, click yes

"Gr8 Dane" wrote:

I have two separate spreadsheets created.... pg 1-50, and pgs 50+.. how do i
merge the "pg 50+" into the "pg1-50" as just a second sheet, instead of 2
separate files?