What can I do about long, overlapping bar graph labels?

Here are a few suggestions:

• Use a smaller font. To do this, select the axis.  Then in Prism 3 choose "Format... Text...", in Prism 4 choose "Change... Selected text...", in Prism 5 click on the downsize button () in the toolbar.

• Rotate the labels to be vertical or 45 degrees.  To do this in Prism 3 go to "Format... Bar appearance... Labels", in Prism 4 go to "Change... X axis... Location...", in Prism 5 go to "Change... X Axis... Location of numbering/labeling..." and choose Below, horizontal or Below, angled.  

• Stretch the graph wider to make room.  To do this, select the X axis, then drag the end of the axis to extend it.  

• Instead of using the built-in column labels, create separate text objects using the "T" tool () to create the labels. These text objects let you push the Enter key to break text into multiple lines.  You can align these text boxes by dragging them into place.  Dotted lines will appear when the text boxes are placed correctly (as shown in in the image below).