The recently discovered supernova in M101 (the Pinwheel Galaxy, in the Plough constellation) should be visible through binoculars over the next 9 days.
When it’s cloudless, look to the northern sky. Go to a local spot with low surrounding light pollution. Look for the Plough Constellation. Follow Star 3 to Star 2 and keep going. There you should find an exploding dwarf star that sucked the energy out of a neighbouring big star, too much too quickly, and “burst” – 21 million years ago.
This June 9, 2005 NASA false-color picture shows the supernova remnant of Cassiopeia A.