To view comments:

1.  Go to Analysis, Information Library, and Add a Batches ad-hoc query. 
2.  Drag the Comments field under 'Select Batches fields:' to the 'Results fields to display:' window pane.  
3.  Click Preview results.  

OR

1.  Go to Administration, Email Alerts, and click the Batch assigned alert under Email alert types.  
2.  Click Edit next to Email content.  Select COMMENTS under 'Available merge fields and click the blue right arrow to move that field into the Email body.  Now, when this Email Alert is enabled for a user and they have a batch assigned to them, the comments will show in the body of their e-mail.