Long time no post here, but I thought I would chime in since I sold my VX some time ago to get in to motorcycles.
First thing I would do, as was mentioned earlier, is take the motorcycle beginners training course. I had never ridden a motorcycle before taking the course, and right away you get right in to it. I think everyone wanting a bike should take it to get a good feel of what you're getting yourself in to. Here is a listing of some in Seattle:
http://www.dol.wa.gov/driverslicense/motoschools.html
Another training school option is through Harley Davidson. You can check online or with a dealer to find the courses offered. I believe they use the Buell Blast in their classes, so you can check those out as well. Also mentioned before, they are small... 500cc's is fine for a beginners bike, but if it doesn't fit you then forget about it. I rode a tiny Suzuki 250cc cruizer in class, and it was small... but for class it was fine.
AFTER the class is when I would start looking for something to buy. It doesn't hurt to look around right now if you are serious about it, but I wouldn't buy anything until after passing the class. Think of it as a gift to yourself!!! Definitely look at a used bike. You won't feel as guilty about dropping something you know has been used and that you didn't pay retail for.
One thing I will say... it is discussed a TON on beginner riding forums and such, but I wouldn't recommend the Suzuki SV-650 (and definitely not the SV-650S) as a first bike... especially if you've never been on a bike before. Just because you have some time in the saddle in the class (assuming you take it), you're riding in a controlled, managed environment on little 250cc machines... and even those will get up and go when you jump on it (they will ask you to hit 40mph on the course, and it feels fast when you do it!). As soon as you get out of the class and look at bikes, you have no idea what they can do, and most will do things the little 250's can't even come close to doing. My first bike was a KTM 640cc single (Duke II), which was a little above my abilities, but it was ok... it last 6 months before I bought an 800cc cruizer. Of course, we don't know how mature you are when it comes to handling the power, or how quick you can think when manuvering... so there is a chance you could handle the SV-650 just fine.
The Ninja 500 is usually thought of highly as a beginner bike (and beyond, really). It is pretty sporty, but power is manageable around town, and it will get up and go when needed. There are a lot of nice bikes out there...
By the way, I now ride a Moto Guzzi V11 LeMans.
Adam