it is very easy doing this. Go to MQseries Explorer, and open the queue manager ,and click the queue folder, which displays u all the quesues on the right side. Double click the queue u want to see, and see all the messages. u get all information.
About seeing the data, u double click any one message, and check the DATA tab and u see the data.
hope this will work out. there are many other ways, but this is the easiest way seeing the queue mesage.