Knowing the difference between and properly using relative and absolute cell references can be extremely helpful when putting together a spreadsheet.
Some background on relative and absolute references: http://www.cpearson.com/excel/relative.aspx
There is a quick and easy way to toggle between the two when entering a formula:
- After entering a reference in a formula, hit the F4 key to change to an absolute reference.
- Hitting the key once will make both the row and columns references absolute
- Hitting again will make only the row absolute
- Hitting a third time will make only the column absolute
- Hit enter to complete the formula.
You can also perform this function while editing any existing formula/reference.