What is a Digital SLR Camera, different versions?

I'm thinking of going into photography as a hobby so I wanted to buy a camera.
A Digital SLR Camera would do, but I really don't understand, for example I go to the Nikon Website & they have versions like the D3X or the D3S. And then there's the lenses, I really don't understand it.
And which brand would be better, Canon, Kodak, Nikon?
Which ones Cheaper? How much are the average camera?
I want to know EVERYTHING about EVERYTHING when it comes to photography and cameras.

You are asking us to type an entire book to answer your question.

If you want to learn about SLR camera systems you have 2 choices.

1) (The best way) Take a photography class.

2) Go read some books about SLR camera systems.

Read a lot. You can learn the basics fairly quickly, but there's So MUCH to learn out there. Good news is with digital cameras it's a much faster learning curve cause you see the results instantly.

The D3X, D3S are Way out of the question. Get an entry level DSLR. Nikon or Canon would be the best choices IMO because they are the leaders, have the most 3rd party accessories available to them (like lenses).
The D3100 (Nikon's newest) is very good.

Can't give you a whole run down, you should get a basic camera kit and take classes at a community college or camera shop for more info, but here's some quick tips.

The QUALITY of the picture is dependant on your skill, the light used, and the lens quality. The camera body has very little to do with it. Sure some sensors are better in the higher end cameras, but the BIG difference will be elsewhere.

ISO, Shutter Speed, and Aperture are all measured in F Stops. These are measured in 1/3 intervals. This is the MOST important thing you'll need to understand.

Spend most of your budget on an upgraded lens, a tripod and a flash. If you have to get a cheaper camera body to fit it, do that.

What? You don't just THINK of doing photography as a hobby if you really want good pictures. You have to WANT it really badly, and willing to take classes, read up tutorials, and read the instruction manual 3 times over until you really get what each settings does.

A DSLR camera is a camera where you can change lenses. Reasons for this is because no single lens can cover everything you may ever want to shoot; that's why there's so many to cover different applications such as wildlife, sports, architecture, portraits, macro, and landscape. I'm pretty sure a D3s or D3x is a little overkill for a beginner like you (I know its overkill for me, and I've been shooting for quite some time!). Consider cheaper DSLRs such as the Nikon D3000 or D5000.

All brands that are capable of making DSLRs usually make decent products, the difference in image quality are small enough that it depends mostly on the photographer to produce brilliant pictures, rather than the camera itself. That being said, Canon and Nikon are the two biggest DSLR brands right now, and both are equally as good. If you want to consider Canon, get the Canon Xs, T1i, or T2i.

Canon is best for DSLR camera.

i was googling and found Nikon D3000 10.2MP Digital SLR Camera which is good for beginners.

* 10.2megapixel CCD sensor
* 11-point autofocus system,
* Fast response, Guide mode,
* 3-inch TFT,
* 3 fps continuous shooting allows you to capture fast-moving action at 3 frames per second

http://www.amazon.com/...002JCSV5I/