Why won't my Nikon D3100 take a picture?

Usually it just focuses but then when i actually press the shutter, it won't take the picture. I'm so frustrated, I just bought this camera today and was so excited to start using it. Any help?

I'm going to make a guess here. You didn't get a memory card when you bought the camera. Without a memory card and a place for the captured image to be stored, the camera won't "take the picture".

Now, you can go to the menu and turn off the "no memory card lock", but all that will let you do is practice snapping. Invest in a couple of 2gb cards and a memory card reader. They're pretty inexpensive.

I do hope you'll now sit down and the read the manual that came with it.

You haven't read the instructions that came with your camera yet have you?