There are a number of websites dedicated to documentation of the events of May 1968 in Paris.
For written material (pamphlets, newspapers, etc.), see the May Events Archive, a digitized collection at Simon Frasier University.
For posters, there are digitized collections at Yale University, the University of Toronto, and a private website.
Here is an eyewitness account of the events in the Latin Quarter and photos of striking workers.
In French, you can find slogans, graffiti, eyewitness accounts, and a list of other French-language websites here.