Actually, I'd suggest the Ninja 500... it's not SO much harder to ride, will run a bit smoother, and make freeway speed much easier than the little 250, which screams when you have it up that high. Both are great starter bikes, but when you've been riding for a little while you wont want to have to buy a bigger bike right away, so a bigger starter is a good idea.
Good luck, and be careful!
(For a new rider, or even if you're experienced offroad like I was, I STRONGLY suggest doing one of the weekend safety courses that are held by many riding schools. They are generally available for both beginning and advanced riders, and it basically counts as a rider's test if you need a license. You get a lot of useful information, which just might save your life.)