Zangetsu:
After reading all the replies I came to the conclusion that you are an absolute beginner and are not yet clear of the basics. It is okay, we all were like that only. My suggestion would be to read, read and read and gain sufficient knowledge about the different aspects of photography and then only think of investing so much money in a DSLR system. I am telling "system" because whatever may be your initial plan, you will continue to pour money into the system if you go for a DSLR.
Photography requires dedication of a LOT of your time. I feel one needs to know the technicalities like the English alphabets so that you can effectively capture a photograph. If you stumble with the alphabets, you will face great difficulties in writing an essay.
Although it is true that knowing the technicalities only, and buying costly gear, one will not be able to take great photographs. You need to have the inner eye. For example, we all know to write, but we all will never become great authors / poets.
My genuine suggestion is please spend the next 1 or 2 months only digesting the basics, then come back again and buy your camera based on the options available at that time. Believe me, your joy will be much more when you will buy a cam after having sufficient knowledge in the subject.
A good basic link to start with is this:
Ben's Newbie Guide to Digital SLR Photography - Canon Digital Photography Forums
You will be able to digest this in a few minutes.
Then move on to this:
Digital Photography Tutorials
Another thing, can you tell me what camera do you presently use?
And a footnote:
50mm is the "normal" focal length like sujoyp said, but note that a 50mm lens will be equivalent to 75mm in Nikon and 80mm in Canon DSLRs. (Not talking about the top end full frame). So a 50mm lens will act as a short telephoto. And not at all suitable for indoor in general, unless you want to take portraits indoor

The 35mm f/1.8 from Nikon is a good option for indoor use because of the large aperture. 35mm will give a 52mm equivalent field of view.
Offtopic: Sujoyp, I bought the 55-200VR last week

So now you and me have the same setup except the body