Software
There is a range of social network software packages out there, many of them free. Some focus more on network visualisation, and other focus more on network analytics and statistical analysis of networks. This is not a comprehensive list, but the following represent some commonly used packages:
Introductory reading list
The following represent some introductory reading into the area of social network analysis (SNA), though there are many others.
Interesting academic publications include:
Borgatti, S. P., & Halgin, D. S. (2011). On Network Theory. Organization Science, 22(5), 1168-1181. doi:10.1287/orsc.1100.0641
Borgatti, S. P., Mehra, A., Brass, D. J., & Labianca, G. (2009). Network Analysis in the Social Sciences. Science, 323(5916), 892-895.
Burt, R. S. (1992). Structural holes. Cambridge: Harvard University Press.
Granovetter, M. S. (1973). The Strength of Weak Ties. American Journal of Sociology, 78(6), 1360-1380.
Ibarra, H., & Andrews, S. B. (1993). Power, Social-Influence, and Sense Making - Effects of Network Centrality and Proximity on Employee Perceptions. Administrative Science Quarterly, 38(2), 277-303.
McPherson, M., Smith-Lovin, L., & Cook, J. M. (2001). Birds of a feather: Homophily in social networks. Annual Review of Sociology, 27, 415-444.
Wasserman, S., & Faust, K. (1994). Social network analysis: Methods and applications. Cambridge: Cambridge University Press.