Way to go on the course.
Don't get new bike. I know it's hard, having a new bike is a great feeling but dropping a new bike is the worst. Everybody (ok 99% of everybody) does at least one dumbass thing to their first bike (eg tip it, scratch it, crash it).
Don't get the latest and greatest bike. Learning to survive on a motorcycle should be all you have to worry about during your first year. Don't bother trying to keep up with riders who have years of experience on you. That's an open invitation to a serious accident. They'll understand if you're a couple minutes behind them......it's not a big deal....REALLY.
Not all used bikes have been trashed. Don't forget they're designed to be used hard, and as long as basic maintenance has been done, they should be good for 50 to 100,000 miles easy. Check out the threads on mileage in this site, you'll be amazed. Getting a bike with 15,000 miles on it shouldn't be a problem. There are tons of people who buy a bike, get scared, keep it for a couple years in the garaged, and then finally sell it (could even happen to you). Expect to put $500 into it when you buy it, and you should be set for a long time. I bought a 88 gsxr 750, put put 500 into it, rode it for 20,000 miles and sold it for $300 less than I put into it.
Personally, if I were you, I'd look for a 600 or 750 standard type bike. I know Kawi makes a 750 that's been around for years. Since alot of smart people use these for starter bikes, they haven't been trashed, and there's always a few around. No fairing means less damage when you crash/tip/whatever.
Use the money you save to buy the FULL GEAR. Face it, the first months are the ones you're most likely to need it. Again, there's lots of used stuff....cheap. Don't get a used helmet.
The money you save in 1 or 2 years should be enough to buy the bike of your dreams. The life you save, could be your own.
Motorcycle helmets only start getting comfortable at 10,000 miles. I only buy them well worn. There is nothing more fun than receiving a used helmet via eBay. The first thing you'll notice, if it's good, is a smell when you open the box. The smell is a sign that the previous owner was in it a lot. This means you'll want to be in it a lot, too! A really good used helmet should have sweat stained padding. It's sweat that softens the inside, and gives it a natural finish. Sweating for at least 2,000 hours is the only way to completely wash away resins and glues used to make the helmet. By buying a well worn helmet, you don't have to go through that because another guy did it for you. A helmet that another guy's been sweating in is good to go. Just put your head in it. Buckle the straps and you're set!
When you get in another guy's lid for the first time, you'll wonder why you hadn't done it sooner. It will go on like an old shoe. The smell will be natural. You'll feel awesome in a well worn helmet.