Below is a preliminary listing of data sources relating to social media:

• Datasets published by the International Conference on Web and Social Media http://www.icwsm.org/2015/datasets/datasets/.
• Multi-lingual datasets published by the University of Southampton http://repository.dlsi.ua.es/view/subjects/TEXTMESS_Areas-Recursos/dataset.html.
• Datasets published by the Natural Language Engineering lab at the Technical University of Valencia, Spain http://users.dsic.upv.es/grupos/nle/?file=kop4.php.
• Very interesting work on creating sentiment lexicons published by one of the winners of SemEval-2013 competition  http://www.umiacs.umd.edu/~saif/WebPages/Abstracts/NRC-SentimentAnalysis.htm.
• The Arizona State Data Repository contains at least 18 datasets including nodes and edges at http://socialcomputing.asu.edu/pages/datasets. 
• The Stanford Large Data Set Collection contains a large number of datasets with many having only nodes and edges but some having freestyle text and other information as well at http://snap.stanford.edu/data/index.html.

We hope to add more information about datasets and invite suggestions.

Papers

Below is a preliminary listing of links to papers related to social media: 

Servi, L. D., Analyzing social media data having discontinuous underlying dynamics.  Operations Research Letters. Vol 14, No. 6. Nov 2013. 581-585 (http://dx.doi.org/10.1016/j.orl.2013.07.008).

Members are encouraged to contribute links to their papers.