If you're using excel 2003 or lower, you can:
Insert|Worksheet
from the menubar at the top.

In any version, you can rightclick on one of the worksheet tabs and choose:
Insert...|Worksheet


Rob Reginato wrote:

I keep a separate spreadsheet for each year regarding my car expenses. But
Excel has only 10 tabs at the bottom of the spreadsheet, and I've run out of
space for the coming year. It must be easy to add tabs, only I don't know
how. I use Windows XP.

--

Dave Peterson