Exposure Issues on DSLR camera?

Hi, I have a Nikon D200 dSLR camera and 10.5mm f/2.8 fisheye lens.
I'm currently reading a difficult book about the DSLR photography and I'm confused.

Here is the thing. I just want to take a good picture in the following two cases.
Please advise how I control the settings; like f-stop, shutter speed, ISO, and etc…

(1) "Indoor photo of a living room with windows"
The living room is a little dark because it is indoor, and the view outside of the window is bright. I want to have details on both dark area and light area as well on the photo. I don't have a flash.

(2) "Indoor photo of a bathroom with light bulbs on"
The light from the bulbs are quite bright and it makes the light area too light and the dark area too dark on the photo.

Meter on the bright spots, and use the D200's built-in flash for fill. It's adjustable, so play around with it some.

From what you describe this isn't a camera issue it's an operator issue.

If you understood how cameras work you wouldn't be asking this question. I'd suggest some serious reading about how cameras actually work.

You are basically wanting a camera with a wide dynamic range.
If you set your exposure to properly expose the bright areas, the dark areas will be too dark.
If you set your exposure to properly expose the dark areas, the bright areas will be overexposed (washed out).

Set your exposure to correctly expose your bright areas is the first step. Once you overexpose a digital image, the overexposed areas are gone forever.

You have a number of options:
1. Shoot in raw mode and edit your image in some editor which can handle 16-bit images. You might be able to bring up the dark areas to something usable. If the dark areas are too dark, you'll get noise and/or color confetti.

2. Use HDRI (High Dynamic Range Imaging) methods. This requires a series of images which include correctly exposed light, dark, and midtone areas. Generally, you don't want your exposures steps to be more than 1.3 EV (stops). Only adjust your shutter speed. Adjusting aperture will mess things up since your depth of field will change. You also need a sturdy tripod and your subjects must be stationary since you are merging a series of images. You will need special software to create a single HDRI image. Photoshop has this functionality. There are other free programs out there which work well, but may require some learning to use properly (Tufuse, Enfuse come to mind). Hugin (panoramic stitcher) will do HDRI using Enfuse. Hugin is a free and very nice stitcher.

3. Use a fill flash. This is probably the best way to do this. Easy in concept, takes a bit of experimenting to get things right. See the Strobist blog for good information on this subject. If you're using lights bulbs, you will need to gel your flash to get colors to be right.