The NYPD's SHIELD counterterrorism program has compiled an extensive dossier (pdf) on tomorrow's Occupy Wall Street General Strike, during which protesters hope to shut down New York and cities around the country. Leaked this afternoon, it's probably the most comprehensive document created about tomorrow's protests.
In the six-page "event advisory bulliten," we learn that tomorrow festivities will include more militant actions like the 1pm "Wildcat" march and a "Bike Bloc," where cyclists will attempt to snarl traffic. Then there's the big permitted march involving labor unions at 5:30pm from Union square and a truly frightening-sounding "Guitarmy." (Don't worry, this was all compiled from public sources—mostly form Occupy Wall Street's own website in fact—though no doubt the NYPD has an inside track on any secret stuff as well.)
Perhaps most important for you bridge and tunnel folks:
On the morning of May 1, demonstrators in the boroughs of Brooklyn, Queens, and the Bronx are planning to march into the borough of Manhattan using the various bridges that connect them. It is possible that some of the "Morning Commute" marches will also be used to blockade individual bridges.