Graphs are easy to define,
Choose your chart type and series type.
Choose an X Axis from the column or row elements.
Choose an Y Axis from the data elements (which should be a numeric or date time field).

Then you can have different options (e.g. using another column or row element as a splitter to have one series per value).

Depending on your chart type (Microsoft or NVD3), the layout and options of the charts can be defined in the Model View itself:
Javascript for NVD3 or Properties editing for Microsoft...

For NVD3 Chart, you have to enter into JavaScript and HTML to customize the configuration.
Select the Model View displaying the chart, then edit the 'NVD3 Chart Configuration' property
at the end of the script, there is a sample of title added to the chart, you can uncomment and modify it...
//Title
//svg.append('text').attr('x', 250).attr('y', 390).style('font-weight', 'bold').style('font-size', '14px').text('My chart title');

more info on NVD3 chart at http://nvd3.org/ and http://cmaurer.github.io...d3-directives/index.html


For Microsoft Chart:
Expand the 'Chart X Axis' or 'Chart Y Axis' property in your view, then just enter your text in 'Label'

there is a lot of info on MS chart if you google it...