Beginner Guitar Pitfalls

What are common beginner guitar pitfalls a new player should avoid?
The most common problem you'll encounter as a new guitarist is the feeling of frustration and the desire to give up.  Impatience has probably disqualified more new guitarists than anything else.  
For some reason we forget that, as a beginner, everything you're forcing your body to do on the guitar is new and strange to it.  Your body (and in our case hands) have an amazing ability to adapt to whatever you focus it on and it WILL adapt itself to the point where playing chords and scales seem like second nature.
But, and a big BUT, it does take some time - so this is the most important thing you need to remember:  Keep at it, do not get frustrated and kick impatience in the butt until you reach your goals!
Bad Technique - I've seen hundreds on guitarists trying to play the coolist solo's when they can barely fret a power chord without their instrument sounding like a factory implement.  It's important to get the basics covered well before you move on.  Your long term relationship with your guitar depends on your basic and fundamental technique, so don't move at such a lightning pace, for example, that you reach an advanced lesson before you've got the basic chords memorized.  Refuse to give in to sloppy technique and a mediocre style and before you finish with a given lesson, practice until you've got all elements of the lesson nailed down perfectly. 
Starting with the Heavy stuff - This ties in with the previous point. Many musicians-to-be fall to the temptation of skipping the 'easy stuff' to get to what they consider to be the 'real guitar playing'.  And of course they end up with nothing but bad technique.  Avoid making the same mistake and rather take my lessons course from lesson one.  You'll grow much faster that way...
Avoiding the 'boring' stuff - Many newbies see scales as a bore and a waste of time.  So they skip over it and end up with what?  Yep, bad technique.  Scales can be an great challenge if you motivate yourself to play against a metronome in order to increase your fingerstyle speed.  Scales are also the primary way your hands will develop individual finger strength and your ears will be trained to recognize musical patterns for soloing.
Trying to do it all at once - I like to see it this way:  The guitar learning process is not like jumping into a pool of chords, scales, strums, techniques and trying to swallow everything in one go.  It's rather like a mountain hike that starts at the foot of a hill and takes you to higher levels step-by-step, one level at a time.  Don't try to do it all at once, take it one step at a time.
But Jimi Hendrix can do it! - It's a natural tendency as a new guitarist to compare yourself to an idol, but for many, instead of this leading to inspiration, it leads to frustration.  Don't try and play like your heroes if you're a newbie, rather let them inspire you and allow you to set your goals higher.
Impatience - I've covered this enough, but of all beginner guitar pitfalls this is most common so it's worth another say.  Don't get impatient, keep at it and put a lid on frustration.