Nikon D3100 Screen Display?

I got a Nikon D3100 and when I take pictures, I need to look through the peephole thing to see what I'm taking a picture of. The screen shows details about camera setting and such, but not what the lens is focusing on, like a digital camera screen would show. This gets annoying when trying to take pics without pressing the camera to my head. Can this be changed?

If you find using the optical viewfinder annoying, you're not meant to use a dSLR. Anyway, check to see if the D3100 has LiveView. That's what non-dSLR users look for when forcing their way into dSLRs.

Read your manual for "Live view".

Using the optical viewfinder (eyepiece) is the best way to use your camera. A DSLR is NOT meant to be used as a P&S camera.

Live view will:
1) drain your batteries quicker
2) introduce shake/blur into the images unless you use a tripod
3) will be hard to see in the sunny outdoors.

It would be extremely difficult to hold my camera and big lens at arms length at produce a decent photo… It weighs around 6 pounds (7 if I put the flash on it).

"like a digital camera screen would show"

Incredibly, too many novice DSLR users expect their new cameras to behave like bulked-up versions of their beloved point-and-shoots. 100% of the pros I work with use that "peephole" to capture the images that earn our living. 0% of us use the liveview on a regular basis. Of the thousands of photos I've taken the last year, I think I've used the liveview on my D300 for about a dozen shots, and only because I was shooting over the heads of a crowd. Using liveview as a regular way of shooting guarantees you'll have most of your photos blurred.

Now that I've gotten that off my chest, here's your answer.

Rotate the lever surrounding the red dot on the back of your camera body. It's a lever labeled [LV].

Here's a demo for you.

BTW, it's in your manual.

Try to take a photo on a bright-sunny day, and you will appreciate the viewfinder.