Chuck Hawks of Motorcycles & Riding wrote a fabulous article on Good First Motorcycles that includes the following advice.
Cruisers and standards are usually a better choice for the beginning rider than sport bikes. Modern sport bikes do what they do extremely well (which is go around corners–or a racetrack–at high speed), but they are often not very good for much else. Cruisers and standards are more versatile, at home on city streets, country lanes, and the interstate. They are equally suitable for commuting, weekend rides, the occasional longer trip, are generally easier to maneuver at low speed (where a tip-over is most likely), and are a little less likely to encourage overly aggressive riding.
I urge all you newbies to read it and heed it, especially this part:
To use my military aviation analogy for the last time, starting with one of these machines is like trying to learn to fly in a combat aircraft. The most typical accident for the beginner on a new 600cc sport bike is caused by a loss of control the very first time the bike is ridden, usually within a couple miles of the dealership from which he or she bought the bike. This is not an encouraging statistic. These are not machines for the youthful or immature rider. The lure of power and speed represented by such machines will almost certainly overcome the self-control of such riders, often with tragic results. If you are not over thirty, a mature and responsible thirty, do yourself and your loved ones a favor and learn on a lighter, less powerful motorcycle.