Abhi,
You have your DSLR with you. It's a way better than camerasim (no offense Pranav).
No offence taken buddy
Yep, I absolutely agree that the best way to learn is by practising, but that camerasim is for ppl like me who are sometimes just too lazy to go through the cycle of shoot-view-correct on a camera
@OP: Never fear to experiment, afterall in the digicams, what do you have to lose anyway... Take as many pics as possible, of anything..
And since you are new to DSLRs, I'd suggest starting off with brightly lit subjects in Auto mode of the camera, like outdoors during day or close to windows.
To start off remember these:
At any given point of time
Shutter/exposure time : Longer means brighter photo (but may get blurry if the subject moves too fast)
ISO: Higher number means brighter photo (but above ISO800 you'll start to see noise, those green and red dots in the pic)
aperture/f-stop : How wide the camera 'eye' opens. (For the time being forget this part. Its important to know this, but you can learn this as you get more comfortable with the camera)
And finally- Get to know your camera. Even if you dont know how a particular setting will affect the image, learn how to set/adjust it anyways. I cannot overstress how important this is.
Have fun, and as you start getting doubts, ask the friendly guys over here