Beginner motorcycle weight for female?

I want to know what is the best STREET bike to learn on. I have riden a dirt bike many times before. I want to get a street bike. (sport) I am 5'6" and only 120lbs. So I don't know WHAT to get. 400lbs seems like it would be too much!
What should I be looking for? And what is the lowest weight for a street bike?

2008 Kawasaki Ninja 250R. The best beginner bike there is. They totally redesigned the new 08 and it looks awesome. It only weighs 333 pounds dry. You should be able to handle it well.

http://www.kawasaki.com/Products/detail....

If you have good experience riding dirt bikes which is a plus for you and you want to move in to a sport bike class look more towards the Buell Blast, it has almost 3 inches lower seat height and only 30lbs heavier than the ninja but that extra weight is in the lower center of gravity if you notice the exhaust is under the bike and it is so perfectly balanced with you standing and it between your legs it feels more like a scooter. Also since you have ridden before, the little 250cc ninja will feel powerless and weak after about 200 miles of riding and you will be looking to up-grade probably in a month or two, just look at how many 250 Rebels and Ninjas are for sale with 200-400 miles on them. On the other hand the Buell has a 500cc motor and very mild manners until you are ready to have some fun, and then you will NOT get tired of this one.

artgrantz and dale have good input.
Main thing would be for you to go sit on the various models/makes available to see what fits your body the best. Being a dirtbiker you know being able to stand flatfoot when astride is important for control. At 5'6 you should be able to handle most of the bikes out there.
Even though you do have some skills, you may want to consider a second hand bike to learn on while you sharpen up on street riding. Weight should not count as a endall factor unless you plan to carry the bike. Weight does count on how the bike handles under different conditions.
Talk up the local riders to get some person to person input on what bikes are more forgiving in tight situations, any bikes that tend to have issues with maintenance, handling, insurance, etc..

edit: I suggest JustPeachy clean the keyboard. Mine does the same when it gets dusty or hubby drops too many sandwich crumbs on it.

Unless you plan on carrying it the weight isn't important. How it fits you is what matters.
Take the MSF class and see how the 250s they provide feel to you.
http://www.msf-usa.org
A cruiser will have a lower seat than a sport bike making it better for someone who isn't tall.
The 600cc Honda Shadow VLX is very easy to control and ride.

I staarted out on a Honda F3, im aabout yoour ssize,,,I dont knoww whaat is with the double letterrs. I find thaa t tthe GSXR is the best for me, the foottpegs aare aaa tt aa How bout you emaaill mee?
I feell stupid cuz i cant control thiss.. emaail meek?

Dont get something that you cant right if you drop it, thats embarrassing.

look up a ninja 250 I would start there