What version? It'll make a difference as 2007 has become a lot "easier" for basic users but harder to talk people through.
Firstly, use the print preview to make sure you get it right rather than wasting time and pages. Command to get the print preview are Ctrl-P then W
It's possible that someone has set the scaling to be wrong. Go into the page set up (in 2003 or previous versions, that's Alt-F > U in 2007 it's the "Size" icon on the Page Layout tab). On the Page Setup box, choose the number of pages wide and tall that you want (possibly 1 and 1 from what you've said) and it'll resize. Check the print preview again.
If there's a lot of blank space, it's possible that someone has set a huge print area. If you are using 2003 or previous, then the commands to clear the print area are Alt-F > T > C That will reset the print area so it'll only print the cells with information in them.
If it is still selecting an area larger than the bit you want to print, someone has put some rogue spaces into cells (bane of my bloody life!). Use left-click and drag on the mouse to select the area that you do want to print, then Alf-F > T > S will set your selection to be the print area.
Although this is all guesses. If it's not sensitive info, you can send me the file if you want.