As quantitative analysis stays very important, but becomes more and more popular and easy to do, I would like to give a brief overview about tools I found that can help you to do this. The tools have different strength and weaknesses and also different pricing and license models. I hope you find it helpful. If you have additional suggestions, please let me know.
Overview about different topics around social visualization
Have fun reading and trying. The list and article will be expanded if I find some more interesting tools.