I've developed this chart as an easy reference for table side x-ray help.  The angles and positioning for both dogs and cats is great for laminating to keep near your dental table.  The positioning chart is an abbreviated version but includes image troubleshooting.  For a more comprehensive guide, see the VetNerd Guide which also includes the charts. 
 
This is useful by itself but is also included in on-site clinical skills training.  You can book a webinar for more interactive training as well!