Good for you!

Hopefully you're taking a rider training course?
My first bike was a '95 Ninja 500. It was comfortable, I wasn't too hunched over. It was light, and handled well. It had enough power to keep me interested, but not so much as to get a newbie into trouble. I had that bike for 3 years, it was a great bike to learn on.
Check out insurance before you buy. (My Versys is insured with Primmum) An older Katana 600 might not be too bad. For a beginner I'd stay away from the 750, it's heavier, more powerful, and might be really expensive for a new rider to insure. The GS500F is also a great choice. You should be able to get into a newer Ninja 250 for your budget as well.
I can understand not wanting to upgrade every year or so. The little Honda CB125 might be good to learn on, but you'll get bored of it quickly.
Pictures when you buy one!!!
