Click the Styles tab of the layer that you would like to configure.
You can select a symbol from a list of built in symbols or choose to upload from file or a link on the web.
Simple markers come in various shapes. You can easily configure the color and transparency.
Unique Value Renderer
You must set the rendering field in order to select unique values. Once you have made a selection the Blue Spatial will allow you to add available unique values individually or all at once.
Click the links with the unique values to set the symbols for those values.
Class Breaks Renderer
When you select the class breaks Renderer you can use the slider to adjust the range for each class. You can also change the number of classes by updating the Total classes field. Use the links which show the range below the slider to set the symbol for each class.