Earlier today, CERN released the first set of publicly available data along with some preliminary tools for visualization and analysis, all of which can be located here. Currently, a small amount of CMS data is available, while data from ATLAS, LHCb, and ALICE will be uploaded in the coming months/years. There is a small amount of data from each experiment available under the “Education” area, so there is a little bit of info for things like visualizing data and running some toy analyses. For CMS, actually performing an analysis of comparable quality to published papers is probably impossible without access to the full CMS software framework and software/detector/beam documentation (as well as connections to members of the collaboration who are willing to help you), but it might be a nice way to get a sense of what analyzers actually do in these experiments. It looks like the data that was released is already processed, so users won’t be able to access raw detector data. No Monte Carlo production files are available at this time.