Reason bigger displacement bikes (600+ cc) are not good for starters is they have so much power that they could get the newbie into trouble faster than one could figure what is happening. Besides a lot of riding skills have to do with leaning the bike in curves and turns. The lighter bikes tend to inspire more confidence to the newbie than the heavier ones.
There are some good starter bikes out there, depending on your interest on the type - sport, standard, cruiser, etc... typically 250cc - 600 cc are light to learn to lean the bikes. They are not terribly fast, but that's what keeps you out of major disaster.
One of the best starter bikes is the Ninja 250 - light, fast enough to be on the highway, cool looking without letting others know its small, inexpensive to buy, insure and run. The new TU250 is also a cool bike. GS500, SV650are good ones too. Buy a 1 or 2 year old used bike for starting out, there is a very good chance the newbie will drop the bike, better an inexpensive used one than a new one.
Don't forget to take the MSP course before starting to ride, could save your life... Good luck.
