spiderdust

First:

Watch the movie Pitch Black. If you don't watch this first, you definitely won't understand what's going on when you're watching The Chronicles of Riddick.

Second:

Go down to Blockbuster (or the video rental place of your choice) and rent an animated film called The Chronicles of Riddick: Dark Fury. This is the story of what happened in between Pitch Black and Chronicles. It may be hard to find, it just came out. In some baffling business move, Universal released this a whole week after Chronicles was released in the theatres. If they had released it much earlier, I'm sure fewer people would have been sitting in the audiences, saying, "Huh?!?"

And lastly:

After you've done all that, go to your local theatre and buy a ticket for The Chronicles of Riddick.

If you've decided to ignore my advice & run to the theatre without any preparation, you may still enjoy it. You'll be confused, but the special effects are cool, and the plot reminded me of Macbeth, Julius Caesar, The Matrix Trilogy, and Dune, all rolled up into one movie.