depends on what you want, sport, cruiser, dual sport. for a beginner start smaller, remember you can always get bigger when you need it.
cruisers are going to be way more comfortable and thus allow for a better learning platform. Honda makes some great smaller bikes for begingers including the Honda rebel, and also the honda hawk. smaller engines, shorter controls. really would be a good fit for your size. they are in the 250cc range which is freeway legal. if you want sport kawasaki makes the ninja. its smaller comfortable and has a more sporty feel. they can be had in the 250cc to the 500-600cc range as well depending on year you get. do your self a favor,
in my humble opinion, you want to start with a cruiser. its a more natural riding position like on a bicycle and will help you learn safer and quicker. the smaller cruisers can also be had for very cheap and the insurance on them is almost nothing. when your skills get better and your more comfortable then move up in size. take an msf course! it will help. be safe!
