Excel help...

I'm doing a spreadsheet for my boss's cervical cancer program in Vanuatu, and I know you can make cells at the top or on the side of a spreadsheet stay there permanently while the others move across. I need to do this, but I don't know how.

Ok, so that sentence made no sense at all.

Basically, what I need to do is to keep the first few columns or rows (haven't decided yet) on the screen at all times, but I need to scroll down through the columns/rows after. Does that make sense?

Long week. *headdesks*

Help.