What's going on with my nikon D100 camera?

Ok so o try to take pictures but in the lcd section thing it says "Fee" what is this? And some tips on taking better pictures clear, pretty portraits?

The lens' aperture ring should be set (and locked) at the minimum aperture (biggest number). You can download a.pdf manual from the Nikon website, I strongly recommend you read it.

The trick to portraiture is using a slightly longer lens (the 55mm end of an 18-55mm lens is a good start) take a step back from your subject, focus on the eyes and set the widest aperture setting you can get away with on either Manual or Aperture Priority.

The really important things about portraits are light, focus, framing, composition.

Light is important because done correctly it can add dimension to the photo as in give it depth.
Focus is critical… That's a no brainer.
Framing is important because of balance for the viewer's eye.
Composition especially when there's more than one person in your portrait.

Lens, of course the lens is important. I shoot all my portraits with my 50mm f/1.8, normally under available in home window light because the look is soft and very clean.

Http://support.nikonusa.com/app/answers/detail/a_id/2605/~/what-does-the-fee-or-f---error-message-displayed-on-an-slr-camera-mean%3F

Most likely your lens isn't fully mounted. Try taking it off and putting it back on again. In the off chance that the electrical contacts aren't making contact, try rubbing a pencil eraser over them.

Better portraits?
- Get more light: Daylight is excellent. Your desk lamp at night is not.
- Keep some distance: Photos shot at arm's length typically look terrible, with 'bloated features' and pale coloring if there was flash. Five feet is a good start. Further away with a telephoto lens is better.

Nothing wrong with your camera, your lens is not set properly.

On Nikon "D" lenses, there's an aperture ring. It must be set at f/22 for the camera to adjust the aperture. Most Nikon lenses with an aperture ring have a locking mechanism to prevent you from changing the aperture once it is set to f/22.

Get in the habit of using the lock, so that you don't inadvertently rotate the ring from f/22 as you handle your camera.

Or if you go to manual mode, the camera will let you adjust the aperture ring on the lens, but most folks prefer to set the aperture via the camera's controls.

The aperture-ring lenses exist to support older cameras, and most of the newer lenses Nikon manufacturers ("G" lenses), no longer have the aperture ring, so this is not an issue.

Set lens aperture ring to largest f/number. If there's a lock, use it.

How to take better pictures? Learn photography. If you don't want to do that, at least shoot under lots of light.