Journal entries should be at least a page in length, and should be about your reaction and reflections on the reading in question.  What did you think about the piece you read?  Did you like it?  Dislike it?  Was it confusing?  Did it cause you to think more on the subject?  If so, what?  Did you make any connections with this piece and other things in popular culture or your life?  Do you think the piece has any flaws?  What would make it a stronger position?  Theres no right or wrong answer really, it is just about your reflections on the piece.  But do be clear and detailed.