BACK

The back, I love this bodypart!  You will notice that I don't include any bent over type back exercises...I just think they can be too harmful to the lower back.  If you real want density though, go ahead..but me..I'm trying to spread my lats like below!!

Lat Pulldowns

For those that don't have access to this machine, find one...seriously, just do pull-ups then.  I've actually heard that pull-ups are more productive, but like the Parallel Bar Dip, if you can't do it because of lack of stregth   the point is moot.  

The hands are to be about shoulder width apart, (forget that wide grip stuff..it doesn't spread your lats anymore than a narrow grip), with your palms facing you.   This grip allows your back muscles time to get tired before your forearm muscles do.  Don't believe me?  Try it both way, palms facing front, and palms facing back, and see which one allows you to do more reps before your forearms give out.

Use the thigh support to keep yourself rooted.  Now from the starting position with arms fully extended, lean back slightly so that you are about 10 degrees from vertical.  Slowly bring the weight down until it is at about sternum level.  Now this is important; do not crunch your shoulders down to help you pull the weight down.   In fact, as you pull the bar to your sternum, push your shoulders back, as if you were trying to put your shoulder blades together.  Your elbows should be at your sides too, not flared out in some abnormal position.  Keep the contracted position for about 1 second.  Slowly let the bar go back up..don't just relax and let the bar yank your arms out of your sockets.  You also don't need to do that super stretch maneuver at the top either (you know, where the term "Full Range of Motion" comes to mind.)  Keep your arms slightly bent, and don't completely round out your shoulders.

Shrugs

The only thing I can say about this exercise (that everybody should know how to do), is don't do any of that rotating shoulder mumbo jumbo at the top of the movement  that people might have told you about..the trap muscles do one thing..lift your shoulders..that's it.