So many questions.
My advice to these photographers generally surprises them.
In my humble opinion, there is ONE LENS to rule them all. My go-to piece of glass. If I had to sell the rest of my lenses, it's the one that I would keep. It's the one that has survived everything I've been able to throw at it, and the one lens I have beat on the longest.
It's the 50mm F/1.8
All images courtesy of nikonusa.com
This should *not* surprise anyone. The 50mm prime is the oldest trick in the book. It is incredibly versatile, inexpensive, small (low profile) and lighter than any other lens.
Still, the people I talk to don't WANT to hear that the 50mm is my favorite lens. They want to hear that the 70-200mm F/2.8 or the 400 F/2.8 or the 600 F/4 is my favorite lens, because all those lenses are hideously expensive, and thus generally out of reach for these beginners and amateurs who don't have thousands to spend on glass.
They can say, "Well it isn't my fault that my pictures suck, I don't have the right gear, I don't have the money. If I could only have ____, then I'd be a better photographer."
On the other hand, a $125 or $220 lens?* Anyone can buy that with a little bit of smart spending/saving. Cut back on your coffee or cigarette or energy drink habit and you've saved enough to buy one in a month or two.
If the gear you need is within your reach, it becomes YOUR fault that your pictures suck. It becomes your problem that you haven't spent any time thinking critically about how to communicate with a still image. It becomes your fault that you don't care enough to take your time to compose an image worth sharing. All of a sudden, when you realize that gear is not the issue, all your shortcomings as a photographer become your problem.
Of course this is stupid. The fact that you never bothered to learn proper exposure has always been your problem, but you used to be able to brush it off and pretend it wasn't your fault.
Those damn camera companies just make things too damn expensive. Damn THEM!
Uh uh. No dice.
Do yourself a favor, buy a 50mm prime. Use it exclusively for a week or a month. Put a few hundred frames through it. Something tells me that you too will discover its power.
The one lens.
To rule them all.
* Nikon sells two version of the 50mm F/1.8. One is the AF-D and the other is the AF-G. The D series will work on the prosumer (D300s) and professional (D4) bodies. The G will work on the lower-end consumer bodies (D90, D3000, etc) as well as the pro and prosumer bodies.
Curiously enough, the version for prosumer bodies is nearly $100 CHEAPER than the G series lens.
I'm guessing they did it to boost sales of the 35mm F/1.8, which is the DX equivalent of the 50mm. Also an excellent lens at $200.
When I bought mine, I got it for $106 plus tax. Brand new. Retail.
You can still get the same (superior) model that I have (with an aperture ring) for $125 on Amazon or $135 from Nikon