Have you purchased the D5300 yet? If your budget is $1000, going full frame just is too much cash. You'd be looking at $1800 for a used D800, or $2400 for a new D750... both good options right now. But that's just the body. I would recommend full frame though if your budget could be tripled... may sound silly, but the resale value will remain good on a body like that (it's not likely to plummet over the course of a month, it will steadily decrease in value over the years by 10-15% per year). The reason why something like a D750 or D800 would be nice is because they offer about 2 stops of visibly better high ISO performance, the viewfinders are bigger, you don't have to deal with the crop factor, and you get a thinner depth of field. Something that took me a long while to learn as a beginner is that if you shoot at say f1.8 on a crop sensor (D5300), you actually get the depth of field equivalent to about f2.8 on full frame. If you shoot at f4 on a crop sensor, that's going to be the depth of field of an f6 on full frame. So if you pick up a 35mm f1.8 lens and shoot it at f1.8, it will produce images that look like what comes out of a full frame set to 50mm and f2.8 (if we're comparing depth of field and field of view).
Nevertheless, I have a crop sensor camera as well. Definitely not a *bad* thing... but if you stick with the hobby, you'll likely end up wanting a full frame camera pretty quick. Is it necessary? Nope.
Personally I recommend the 18-35 Sigma Art lens. It's a constant f1.8 aperture. Since you're a beginner, you can't really know if that very limited zoom range will suit you though... I don't recommend you go out and buy this lens immediately (it's $800 USD anyways), but I got it after owning a 16-85mm VR Nikon lens (I sold that zoom lens). I prefer having a faster aperture (being able to blur the out of focus areas at shorter focal lengths), rather than a slow aperture and a larger zoom range. The constant f1.8 means you also get much much better low light capabilities out of your camera. If you shoot at f1.8 and you compare that to f2.8, you're letting in 2 full stops of light more at f1.8. That means a shutter speed of 1/40 at f2.8 can be 1/160 at f1.8. That can mean the difference between getting the shot, and not getting the shot.
Here's my recommendation: Take a serious look at the 85mm 1.8G ($500), 50mm 1.8G ($200) , and 35mm 1.8G DX ($200) lenses. They're all excellent, the 85mm 1.8G is 90% what the 85mm 1.4G is, and the 85mm 1.4G is a $2000 lens. The 50mm 1.8G is just good value. The 35mm 1.8G DX is also just good value (not the FX version though, it's a waste of money). Other prime lenses you might encounter if you research at an affordable range are the 20mm 1.8G, 28mm 1.8G, 40mm micro... ignore those lenses for a camera such as the D5300. The 28mm 1.8G has some focus issues, it's good value on FX, but on DX it approaches the price of just getting an 18-35 Art which will do what it does and a lot more. The 20mm 1.8G also is somewhat pricey for DX, and again the 18-35 Art overlaps it. The 40mm Micro is just overall pretty bad.
As far as zooms go, I already mentioned the Sigma 18-35 Art. I love it. If you want a convenient fairly fast zoom lens, the Sigma 17-50 f2.8 OS is also worth taking a look at, it's a good range with a decent aperture. If you want a convenient zoom range, there's the 18-105, 18-200, etc... but those, to me, are slow lenses that produce disappointing results unless if you just want to snap photos from a beach chair in Jpeg.
If you want to shoot birds, the crop factor of the D5300 is advantageous (you get more reach out of your lenses). The 70-300 VR is an alright lens, I have it, it's decent. It's not a birding lens, it's more of a camping trip lens to get shots of animals that are further away. It's alright for sports as well if you're shooting in broad daylight. I do recommend the lens, but just barely... at 300mm it's not the sharpest. The Tamron 150-600 is an excellent lens if you want a behemoth at the price of just over $1000 that has lots of reach... if you want to do birding. Sigma is just in the process of releasing their 150-600 as well. This may just be a pointless comment... the 70-300 is $400 and good for starting out and beyond... I still have mine, and I have a tendency to sell things I don't want.
Shoot RAW, use Adobe Lightroom.
This post was edited by Canadian_Man on Oct 21 2014 10:20pm