Hi Stephanie,
You are very close.
Following along from Chip's site and your comments, try these steps:
1) Select the area you wanted "banded"
2) Format | Conditional Formatting
3) Enter this equation...=MOD(ROW()-1,2)+1<=1
4) Be sure to hit the format button and choose a pattern
5) OK
Now you have your banded area on the spreadsheet.
Regards,
Kevin