Gephi is somewhat easy to use (no programming required), and is actually quite fun. It’s also computationally intensive, with some upper limits on how much it can process at any one time.
Download Gephi here.
Main project page here.
If you managed to completely extract data, following through the instructions on OpenRefine, you can use the CSV file you created from there.
If you didn’t, there is sample data to download here.
robbie fordyce : research 