Is it okay to use Nikkor 50mm F/1.8G to my D5000? Especially for indoor use?

I'm confuse which will I choose between 35mm F1.8G. And also I want to how far from the subject if I will use the 50mm F1.8G since it is a FX lens.

The AF-S 50 mm f/1.8 is a portrait lens.

To see which focal length lens is more appropriate for your use, visit a proper camera store an put both lenses on your camera to see how the perform.

On a 35mm film camera or full-frame DSLR a 50mm lens is considered a "normal" lens because its angle of view approximates that of the human eye. A focal length of between 85mm to 105mm is considered an ideal portrait focal length on a 35mm film camera or full-frame DSLR.

On your D5000, which has a 1.5x "crop factor" the 50mm lens will have the angle of view of an 80mm lens on a 35mm film camera or full-frame DSLR. So on your D5000 the 50mm makes a good portrait lens.

The 35mm lens on your D5000 will have the angle of view of a 52.2mm lens on a 35mm film camera or full-frame DSLR. This makes the 35mm an acceptable "normal" lens on your D5000.

So if your goal is to capture a scene close to how you saw it with your eyes then use the 35mm lens, If your goal is making portraits then go with the 50mm lens.

When using a 35mm lens on a DX camera, it is true that it's "apparent" focal length is 50mm. However, even though the focal length appears to change, the lens retain's the characteristics of the 35mm lens - namely perspective distortion.

So it may not always be appropriate for your "normal" lens, especially if you are prone to taking photos of people, as the perspective distortion will alter their characteristics a bit.

For a good explanation of perspective distortion on the 35mm lens, visit: http://www.althephoto.com/lenses/35mmprime.php