Show me how to format cell alignment in Microsoft Excel 2007

Excel -> Microsoft Excel 2007

Problem: Some values in my spreadsheet are right-aligned and others are left-aligned.

Open Microsoft Excel 2007
Select a cell
On the "Home" tab, under the "Alignment" section, click the "Align Text Left" button (it looks like several lines of different length all aligned to the left edge of the button)
Click the "Center" button (it looks like several lines of different length all centered on the button)
Click the "Align Text Right" button (it looks like several lines of different length all aligned to the right edge of the button)
Click the "Top Align" button (it looks like several lines of different length all aligned to the top edge of the button)
Click the "Middle Align" button (it looks like several lines of different length all aligned to the middle of the button)
Click the "Bottom Align" button (it looks like several lines of different length all aligned to the bottom edge of the button)
Click the "Increase Indent" button (it looks like several lines of different length with a right-pointing arrow in front of them)
Click the "Decrease Indent" button (it looks like several lines of different length with a left-pointing arrow in front of them)