diff --git a/graph.h b/graph.h
index e04b5ff..9eb33d7 100644
--- a/graph.h
+++ b/graph.h
@@ -3,27 +3,75 @@
 
 struct graph;
 
-#define INVISIBLE_COLOR (-1.0)
 
 struct graph *graph_new(unsigned int xdim, unsigned int ydim, const char *font);
+/* graph_new() Returns a new graph structure of the given dimensions and font */
 void graph_set_size(struct graph *g, unsigned int xdim, unsigned int ydim);
+/* graph_set_size() Changes the size of a graph to the given dimensions. */ 
 void bar_graph_draw(struct graph *g, cairo_t *cr);
+/* bar_graph_draw() draws the given graph as a bar graph */
 void line_graph_draw(struct graph *g, cairo_t *cr);
+/* line_graph_draw draws the given graph as a line graph */
 void line_graph_set_data_count_limit(struct graph *g, int per_label_limit);
+/* line_graph_set_data_count_limit() limits the amount of data which can
+ * be added to a line graph.  Once the limit is reached, the oldest data 
+ * is discarded as new data is added
+ */
 void graph_title(struct graph *g, const char *title);
+/* graph_title() sets the main title of the graph to the given string */
 void graph_x_title(struct graph *g, const char *title);
+/* graph_x_title() sets the title of the x axis to the given string */
 void graph_y_title(struct graph *g, const char *title);
+/* graph_y_title() sets the title of the y axis to the given string */
 void graph_add_label(struct graph *g, const char *label);
+/* graph_add_label() adds a new "stream" of data to be graphed.
+ * For line charts, each label is a separate line on the graph.
+ * For bar charts, each label is a grouping of columns on the x-axis
+ * For example:
+ *
+ *  |  *                          | **
+ *  |   *      xxxxxxxx           | **
+ *  |    ***  x                   | **              **
+ *  |       *x       ****         | **      **      **
+ *  |    xxxx*  *****             | ** xx   ** xx   **
+ *  |   x     **                  | ** xx   ** xx   ** xx
+ *  |  x                          | ** xx   ** xx   ** xx
+ *  -----------------------       -------------------------
+ *                                    A       B       C
+ *
+ * For a line graph, the 'x's     For a bar graph, 
+ * would be on one "label", and   'A', 'B', and 'C'
+ * the '*'s would be on another   are the labels.
+ * label.
+ */
+
 int graph_add_data(struct graph *g, const char *label, const double value);
+/* graph_add_data() is used to add data to the labels of a bar graph */
 int graph_add_xy_data(struct graph *g, const char *label,
 		const double x, const double y);
+/* graph_add_xy_data is used to add data to the labels of a line graph */
+
 void graph_set_color(struct graph *g, const char *label,
 		double red, double green, double blue);
+#define INVISIBLE_COLOR (-1.0)
+/* graph_set_color is used to set the color used to plot the data in
+ * a line graph.  INVISIBLE_COLOR can be used to plot the data invisibly.
+ * Invisible data will have the same effect on the scaling of the axes
+ * as visible data.
+ */
+
 void graph_free(struct graph *bg);
+/* free a graph allocated by graph_new() */
 
 typedef void (*graph_axis_unit_change_callback)(struct graph *g, int power_of_ten);
 void graph_x_axis_unit_change_notify(struct graph *g, graph_axis_unit_change_callback f);
 void graph_y_axis_unit_change_notify(struct graph *g, graph_axis_unit_change_callback f);
+/* The labels used on the x and y axes may be shortened.  You can register for callbacks
+ * so that you can know how the labels are shorted, typically used to adjust the axis
+ * titles to display the proper units.  The power_of_ten parameter indicates what power
+ * of ten the labels have been divided by (9, 6, 3, or 0, corresponding to billions,
+ * millions, thousands and ones. 
+ */ 
 
 #endif