I am getting a new Nikon D5100 (with 18-55mm VR Lens Kit). This is going to be my first DSLR. I wanted to get some tips from you guys on how to maintain it in the long term. I am getting a 52mm UV Protector Filter, as I read that it would do well to keep the lens clean.
Are there any precautions I need to take?
I would also appreciate if someone can suggest some reading material (paperback or online).
Since the question is a bit too broad to "fully answer," I'll just volunteer some tips. Hopefully with everyone's ideas combined, you'll come up with a good idea of how to maintain your camera.
I've had a similar camera (Canon t1i), and it's survived two years of intense use by me and a handful of teenage students working with these guidelines...
Get a bag/backpack for your gear with padding. Doesn't have to be huge, but it should fit your camera body, the lens you have, accessories (batteries, chargers, etc), and leave room for another lens or two. This makes travel easier, and it can't get caked in dust in a bag.
Always put the body cap back on your camera, and put both the front and rear lens cap on the lens if you don't leave the lens on the camera. I hate when I see people toss a body/lens around without the cap on. You could leave the camera assembled all the time if you only have one lens, but I almost always detach my lens and pack everything up when I'm not using the camera.
Keep a microfiber cloth (I use these, but anything similar would be good) in your bag to wipe down your lens, and replace/wash the cloth if it appears to be getting dirty. If you get debris on the cloth and wipe your lens, that can be bad. It also helps to keep the lens cap on the lens when you're not using it, so that you don't accidentally get fingerprints on the lens (doesn't happen to me often; but when my students are using the camera it's a whole 'nother story).
If your lens comes with a lens hood, use it. It'll help protect the glass from getting bumped/scratched. The kit lens probably doesn't come with a hood, but you can get an off brand one pretty cheap on Amazon. [Thanks to Itai for the comment]
Extreme heat is no good. So I wouldn't leave your camera in the trunk of your car 24-7 if you live in a hot climate.
Be careful around water. A drizzling rain won't kill your camera, but just don't disassemble the camera or open the memory card door when your outside. If you're out in heavy rain, get something to cover the body of the camera (a freezer ziploc bag is great). The end of the lens can stick out fine, it's the electronics you want to protect.
The main thing is to keep the camera and lenses clean and dry. Dirt and dust are, of course, just terrible for both sensor and lenses. Rain, condensation, salt spray, etc. won't do the camera any favors either.
Aside from environmental issues, just make sure that you treat the camera with respect -- don't toss it around, keep it in a protective case, make sure that anyone that uses it will treat it the same way you would.
Get some periodic maintenance done. Just as with your car needing a lube job every 10.000 miles, so your camera benefits from being checked out once every other year or so (or after say 10.000 pictures).
Nikon service centers do the job for a small fee. For example I spent 100 Euro a while ago to get my D200 cleaned, checked out, and have everything tightened, which included replacing the rubber grips which had come loose (without that it'd have been half that money).
While more important if your cameras get worked hard, it can't hurt to have a professional technician look at it once in a while and do some preventive maintenance. Of course the relative cost to the purchase price of a new body is less favourable at your end of the scale than it is for professional bodies.
I'm surprised no-one has mentioned it so far, but the best way to protect your DSLR is with insurance. A UV filter may protect against low speed impacts to the front of a lens, but wont protect against side impacts or hard impacts to the front, let alone water damage, fire or theft.
You can probably add it to your household insurance, which will sometimes even cover use out of the house. Or get a camera specific insurance policy (this might be more expensive).
