To throw in my 2 cents, I'm 16, and in Ontario you can get your G1 at 16. With a G1 you can only drive with a fully licensed driver with 5 years experience in the passenger seat, and as many passengers as there are seatbelts. You can't drive between midnight and 5AM, can't drive on major 400-series highways (100 km/h) unless with a driving instructor, and of course BAC of 0. After 12 months (8 if you take Driver's ed), you do a road test, and if you pass you get your G2, which means you can drive alone, and on all roads in Ontario. There's still restrictions* to how many teenagers between 12 and 5AM (so you can't take 6 drunk kids home from a party in a van and flip it), and BAC of 0, but you're an almost fully licensed driver.
As for me, I took driver's ed so I'm going to get my G2 on June 7th, and I consider myself to be a responsible driver. I don't take dangerous risks, don't speed excessively, and I don't drive aggressively. However, by virtue of my (lack of) experience, I know I'm not a good driver. I think the most important thing for a new driver to be is a responsible driver, drive safely, don't be aggressive, and follow the laws. You've only been driving for a few months, so you don't have enough experience to really be a good driver. However, if you drive responsibly you're more likely to be a good driver as you gain experience.
As you gain more experience driving, that's when you become a good driver. If you're responsible and don't drive like an idiot when you're 16, you're going to be a good, responsible driver at 30. However, if you drive like a moron and drive daddy's truck like a maniac at 16, you're going to be the asshole driver at 30. The ones that cut you off, speed excessively, and drive dangerously always drove dangerously right from the start. If you drive dangerously at 16, odds are you're going to always be a dangerous driver.
I think as a new driver, the most important thing for me to do is to focus on driving safely, and not wrapping my car around a tree. That's why I'm glad that I'm driving a Toyota Corolla. It's the perfect starter car for me, efficient, big enough to carry my hockey equipment, seats 5 (4 comfortably), it's not overly expensive, it's reliable, and it's powerful enough that I can pass and merge safely, but not fast enough to get myself into trouble. Statistically speaking, I'm likely to have a car accident. My goal is to not have one, but statistically I will.
Sure, I'd love to have my mom's new '11 VW Golf TDi, but the temptation to be a moron with the amount of torque in that car is too high, and the risk of totalling a brand new car is too much financially, compared to an '03 Corolla. I think the biggest thing us new drivers need to realize, is that even if you're the best teenage driver to walk the earth, odds are you suck. Compared to the average adult driver with >10 years experience, you're an awful driver, and that's OK. All it means is you shouldn't be driving a car that's too powerful for your needs, and should try to be extra cautious. The experience and skill will come in time, and the most important thing is to be as safe as you can be.
On the topic of good first cars, if I didn't have the Corolla, I'd be looking at pretty much any used 4 cylinder sedan/hatchback. Cavalier, Cobalt, Corolla, Matrix, Vibe, Golf (older) Camry, Accord, Neon, Jetta, Focus, etc etc. Powerful enough to be safe, but not fast enough to be dangerous. Of course, reliability is a concern, so I'd be more apt to go with a more reputable manufacturer.
*First 6 months of G2= you, and one teenage passenger maximum between midnight and 5AM, last 6 months= maximum of 3 teen passengers. These regulations don't apply to immediate family members, or if you have a fully licensed driver with 5 years experience in the passenger seat.
In my opinion, being a good driver is dependent on how you behave. If you are not experienced, you should drive more cautiously. If you do that, you are a good driver because you are concerned about your own and others' safety.
