Information about the 2012 transit of Venus--June 5 or 6, depending on where you are--can be found at various web sites, including those of the National Aeronautics and Space Administration (NASA), the National Geographic Daily News ("Transit of Venus 2012--Sun Show Will Be Last for a Century"), and the Royal Observatory at Greenwich.
Here is the Dewey number for transits of Venus:
523.92 Transits of Venus
Two examples of works classed in 523.92 are The Transits of Venus and June 8, 2004: Venus in Transit. (Despite its title, by the way, the second work is not limited to 2004; much of the work treats five Venus transits prior to 2004).