Primarily, the objective of Computational Social Science is to understand human behavior but with computational methods. Traditionally, social science was done offline with surveys. But, with the increase in social information on the Internet could we use that data to know more about humans?
How? There are various methods on how one could do so - network theory, statistics, text mining etc. are some tools that are useful to achieve the objective.
http://www.cs.cornell.edu/home/kleinber/networks-book/
They also made an EdX course for it:
https://www.edx.org/course/networks-crowds-markets-cornellx-...
Social and Economic Networks: Models and Analysis, Stanford
Networks: Friends, Money, and Bytes, Princeton
Sampling People, Networks and Records, Michigan
Applied Social Network Analysis in Python, Michigan
Capstone: Analyzing (Social) Network Data, UCSD
Social Computing, UCSD
Measuring Causal Effect in the Social Sciences, U Copenhagen
Smart Cities, EPFL
Organizational Analysis, Stanford