If you click on a cell in your list, you will see a small grey move handle in the bottom right corner of the blue list border. If you put your mouse pointer on the move handle, it will turn into a double headed arrow. You can then hold down your left mouse button and drag the move handle to resize the list.

You can also right click on a cell in the list, and choose List->Resize List from the list menu

This will display a resize dialogue box where you can type the cell range of the new list directly.

The list itself will be enhanced by a blue and yellow flashing border, and if you wish, you can select a new range with your mouse (the new range you select will be surrounded by the flashing border). If you resize the list, or select a new range, be sure to include the row of column headings, and make sure that the range of the old list is overlapped by the new range.

The Resize List box will let you specify a new range, or if you prefer, the flashing border will let you select a new list range with the mouse.

Pay attention to the Note: in the Resize List dialogue box.

When you are finished click OK and your list will be resized.

If you resize a list to include additional columns, Excel will insert column headings in the top row of the list (Column1, Column2, etc.)

You can modify a column heading by clicking on the cell with the heading you want to change, and editing the heading in the formula bar.

You can format cells in a list with the buttons on the standard toolbar, and you can change the width of the columns or the height of the rows in your list by mouse dragging the lines that separate the column letters or row numbers. You can also add fill color or borders to your lists.

Pretty much anything you can do to modify a standard cell range, you can also do with a list.