By "dead pixels," do you have some dead sensors on your imaging surface? Or are you referring to the "noise" that all digital cameras are subject to?
It the bad pixels are consistently in the same place (I have two Nikon coolpix with this ailment) you can take a shot with the lens cap on, desaturate the image and invert it (make the blacks white and the whites black), and drop it over each full size image as a quick and dirty fix. (This will just make white or colored pixels black, but this is often all that you need.)
If it is camera "noise," keep in mind that the amount of noise increases with:
1) the temperature of the camera (hot days make noisy pictures)
2) the iso setting (the higher the iso, the more noise)
3) the amount of compression that is applied (your image quality or jpeg settings)
4) (indirectly) underexposing the image adds noise.
As far as how much will a stray pixel show in a print? It all depends on how many pixels there are in total. If you have an image that is 300 x 500 pixels, and you print it on a printer at 300 dpi, that pixel will only be 1/300th of an inch.
But you picture will only be an inch by and inch and a half. You can enlarge the picture to say 5 x 7 and your one stray dot will now be about 1/90th of an inch. Now the dot will show up, (but your picture will be so blurry no one will really notice)
to make matters worse. If you do any sharpening, you will create a halo all the way around the bad pixel so that everyone will be sure to see it.
Point is, shoot at as high of a resolution, with as low of an iso, with as little compression as possible, and on a cold day. Then, you will have to worry much less about the single odd pixels.
"When a true genius appears in the world, you may know him by this sign, that the dunces are all in a confederacy against him."
- J Swift