The first thing you should know about short hair is what your hair will do when it is short. Do you have fine hair with little body? GREAT! Short hair is for you! Do you have thick hair with lots of body and curl? Maybe not something you want for the rest of your life.
I am of the latter breed but I think regardless of who you are you fret over making your hair into something it's not. My mother was of the afore mentioned camp and she spent an hour every day curling every strand, teasing, and shellacking it into place. Then the humidity would hit and it turned withery and looked like a hairstyle I would want.
Mine is the opposite. I arise from a lovely slumber to a floret of cauliflower sitting on my head. I straighten and try to pin strands down so they will fall on my head rather than flagging 2" high. Albeit a current resident of the South, I have no desire to don pageant hair and do not ascribe by the words, "the higher the hair the closer to God." Those are not my words, but the words of some other fantastic smart ass.
That being the case, I remember with wistfulness the days where I would roll out of bed, run a brush and some smoothing cream through my hair and walk out the door. Truthfully, I like being able to hide behind a ponytail and pretend my slacker tendencies are a "style." But the Sheltie look had to go and I'm seriously glad I gave short hair another go.