Nikon d50.. when adjusting for exposure in any mode everything is as normal after i take the picture the shutter speed can jump or decrease from say 100th of a sec. to 1000th of a second and that is composing on the same scene thank you..

This has been showing up in the autofocus mode of Nikon DSLRs of all flavors for years. There's some indication it may be due to an underlubricated gear causing the shutter to fire at a faster speed than indicated, but most of the evidence seems to point to a random glitch in the firmware.

What shutter speed(s) are you using? What happens when you use a faster shutter speed? In the S and M modes you are responsible for setting the shutter speed, and you can set it to anything within the camera's range.

The N2000 has Program, Program Hi, Aperture-priority, and Manual exposure modes, with exposure lock and exposure compensation capabilities. It can TTL auto and manual with flash. The meter is full-aperture and center-weighted.
The Program mode sets both the shutter speed and aperture for optimum exposure. You can adjust the exposure if you want to emphasize shutter speed or aperture. The Program Hi mode tries to set a higher shutter speed for action and/or long lenses.
You can download a copy of the manual here if you want to know more about this camera.

The settings depend on what you're trying to say with the picture. You probably wouldn't want the same settings for a portrait as you would for a landscape. Two photographers at the same place and time with identical cameras probably wouldn't use the same settings, as each photographer has his/her personal style.
In the Program mode the camera select the shutter speed and aperture it deems optimal. You can turn the command dial to adjust the exposure, increasing the shutter speed and opening up the aperture, or decreasing the shutter speed and closing down the aperture by turning it the other way. Either way, the exposure itself remains the same.
If you're taking a landscape picture, you'd probably want a small aperture to get the maximum depth of field. If you're taking a portrait, you'd probably want a large aperture to blur the background. If you're taking an action picture, you'd probably want a fast shutter speed to capture the action. Of course, those are just guidelines. Sometimes you want to blur the action, or throw some portion of the picture out of focus. It's up to you. You use the settings to take YOUR picture.

The EM doesn't really have a manual shutter speed setting. It does have a Bulb setting for long exposures and a 1/90 second manual for flash, but otherwise the camera automatically sets the shutter speed to go with the currently selected aperture.

Normally you would set the aperture and let the camera set the shutter speed. You can adjust the shutter speed by pressing the exposure compensation button for +2 stops. You can also adjust the exposure by changing the ASA/ISO setting.

If you need a manual, you can download one from http://butkus.org/chinon/nikon/nikon_em/nikon_em.htm

According to what you say, it seems that you selected B (Bulb) as shutter speed (and MANUAL mode).

First, check whether you are on MANUAL mode ("M"); then, check your shutter speed. If it's really in "bulb" mode, all you have to do is dialing the speed button down to figures that match your subject's light conditions and your other preferences involved in the exposure (ISO, lens apperture).

The r09 is just the display that tells you how many pictures you have in the memory buffer for shooting in continuous mode. There are a few reasons why it might not take a pic in S, but normally it's when it's not in focus. Maybe you have it pointed at something too close for the lens to focus. It also could be that your shutter speed setting is way too fast for the available light.

In S mode, the camera will use your shutter speed setting and adjust the aperature to match the light. If it can't get enough light at the shutter speed set, then it won't expose. Keep in mind this isn't just for exposures that are close to being right, only when the shutter speed is so fast or slow that the exposure isn't in the ballpark.

Try moving your shutter speed up or down.

Press MENU and select the pencil icon to get to the Custom Settings Menu.
First select the "Detailed" mode under Menu > Setup (wrench) Menu > CSM menu, otherwise you'll only to get the first few items!
[R] Menu Reset: This returns everything below to factory default.

You are massively overexposing the picture. Manual mode means you have to set the exposure manually. You need to adjust the settings so that the light meter reads somewhere around the zero mark.

M mode is most useful for flash photography where you want a certain level of ambient illumination in the picture as well.

If you want some control over the camera but don't want to worry about exposure too much, use A and S modes. The manual will explain all of these modes.

The settings in Auto Mode are factory set. If you want to adjust exposure and shutter speeds then you will have to shoot in Manual Mode (TV=Shutter Priority, AV=Aperture Priority, M=Full Manual)