Okay, Im going to tell you like Ive been told a million times..
Your first bike should be something small.. No bigger then a 500cc really. For several reasons.
A. They are a lot cheaper on insurance. Insurance on a sportbike can you a brother! Make sure you check it out first.
B. They dont have quite as much power. Which means, you wont get in trouble quite as fast. They can still hurt you, or worse kill you. The bigger the bike the faster trouble can happen.
C. A little better on gas. Always a good thing, right?
D. Most importantly, price. You can pick a nice one up pretty cheap. This means you can get a newer one that will be more reliable.
My suggestion would be something like a Kawasaki Ninja 250EX or 500EX. These sound small, but trust me.. For your first bike they are plenty fast enough. The 500EX will do 13.3 in the 1/4 mile. Thats pretty damn quick.
My personal favorite is probably a Suzuki GS500. I think they look cool. They dont have fairings that you have to worry about cracking if you drop it. Not quite as fast as a 500EX but still fast enough to give you a rush.
There is a saying in the sportbike world...
"There are 2 types of riders, ones that have wrecked, and ones that havent wrecked yet."
Last thing. If your going to buy a bike, take a Motorcycle Safety Course. This is great for a couple of reasons. You will probably get a insurance discount. You can take the beginner class without having a bike, they supply them. And in some states, passing the MSF training course, allows you to get your license without having the take the maneuverability test for the BMV. The course is cheap. Do yourself the favor and take it. Be safe!!
http://www.msf-usa.org/
For more info on sportbikes and such, go to the forums on
www.sportbikes.net
Its a nice site with a good n00b section for any questions that you may have. They will help you with all the right information. Thats where I have spent a lot of time researching.