Tips on Using Excel (specifics apply to Excel 2003; may differ from Excel 2007)

1. When you go to make a graph, put your cursor in the upper left hand corner of your data or select a box that has all the data in it. Then you can click on the little graph icon on the menu bar and create your graph.

2. Although a bar graph is useful for some data, most data analysis you will do will be points on an x-y graph. Excel has two main selections for making graphs, "line" and "x-y scatter".
The "line" selection will plot your points and connect them with a line automatically. This is usually bad.  For some experiments, you will be expecting a linear relationship among the points, and a line which isn't a "best fit line" will have to be removed. Much more importantly, the "line" selection does NOT give you a linear x axis.  This is a problem because we are usually graphing some response that occurs over time. (Excel has a "time-scale" option, but the smallest units are "days"; useless). For example, in the Lysozyme exercise, the first two data points are 2 minutes apart, the next two are 3 minutes apart, and the rest are 5 minutes apart. If you use the "line" setting, all these data points will be spaced evenly,  so they will all be the same distance apart on the graph regardless of whether they are 2 minutes apart or 5 minutes apart!  Beware!!
The "x-y scatter" selection is far more useful because it will give you a linear x axis regardless of the x axis data.  If your data is listed in the spreadsheet as "0, 5, 45, 20, 15" it will still graph it in the correct order with the points the correct distance apart. The "x-y" selection does NOT automatically run a line through the points, but there is menu selection for connecting the points (with curved or straight lines) for when that is appropriate.  For data when a linear relationship is expected, a trendline (best fit line) can be added after the points are graphed.

3. Step 2 of the "Chart Wizard" has two tabs which are important. Under "Data Range", make sure Excel knows whether your data are in rows or columns. When I worked with the lysozyme data, my data needed to be graphed as columns and Excel had to be told. Under "Series", you have two important things to do. First, make sure the box that mentions "X" has the range for your X axis data (the time points from 0 to 30 minutes). Second, this is the only place you can name each set of points you are graphing. Whatever appears in the "name" box will appear in your "Legend" on your graph. "P. putida - A" is a useful legend, but "Series A" doesn't tell you a darn thing.

4. Step 3 gives you the chance to give your graph a title and label your axes (very important).  Also, some experiments you do may produce data that are all graphed together; in this case, you won't have separate lines, so you won't need a legend.  Step 3 gives you an option for getting rid of the "Legend" box on your graph.

This should get you started. Remember, if you don't know, ASK.