The answers below assume that you are using Crimson 3.0
If you want a single bar graph you will put a square on the display and drag it horizontally or vertically to fill the space you need. Then go into the properties and for the fill mode you will select your fill direction. Then you can give it the tag value and a min and max.
If you are using the bar graph primitive you will enter an array for the value and the count will be how many elements of the array the graph looks at. Once again you also have a min and max to configure for the graph.
In the scatter graph you will need to assign an array for the X and Y axis. The count will be how many elements from each array are polled to fill the graph.