Press TAB to move the selection one cell to the right. Press ENTER to move the selection down one cell.
Say that you're creating a list of salespeople names. The list will also have the dates of sales, with their amounts. So you will need these column titles: Name, Date, and Amount.
You don't need row titles down the left side of the worksheet in this case; the salespeople names will be in the leftmost column.
You would type "Date" in cell B1 and press TAB. Then you'd type "Amount" in cell C1.
After you typed the column titles, you'd click in cell A2 to begin typing the names of the salespeople.
You would type the first name, and then press ENTER to move the selection down one cell to cell A3 (down the column), and then type the next name, and so on.