When you have to work with data visualization, a good first step to start with is Edward Tufte, an American statistician, expert in the presentation of information graphics. I would like to add a quote from Tufte’s book “The visual display of quantitative information“, which I think matters every designer :
” Design is a choice. The theory of visual display of quantitative information consists of principles that generate design options and that guide choices among options. The principles should not be applied rigidly, or in a peerish spirit; they are not logically or mathematically certain; and it is better to violate any principle than to place graceless or inelegant marks on paper. Most principles of design should be greeted with some skepticism, for word authority can dominate our vision, and we may come to see only through the lenses of word authority rather than with our own eyes.
What is to be sought in designs for the display of information is the dear portrayal of complexity. Not the complication of the simple; rather the task of the designer is to give visual access to the subtle and the difficult – that is
the revelation of the complex. “