1. Without any cells selected, click the "Chart Wizard" button, or use the
menus by going to Insert -- Chart.
2. Choose the chart type and sub-type of interest (Line Chart, in your
case), click "Next."
3. Click the "Series" tab, click the "Add" button. For the "Values,",
choose your y-axis values (Column B).
4. For the "Category (X) axis labels," choose your x-axis values (Column C),
click "Next."
5. Fill in your chart options (title, axis titles, etc), click next... etc,
until you finish going through the chart setup (at any time, you should be
able to hit "Finish" which will just give you blank titles and the options
will just be set up as default/auto values).

Hope this helps, Jim