How to use the LCD preview when shooting with Nikon 3100?

I want to use the preview on the LCS screen on my Nikon 3100 but don't seem to work very well - I mean if I swith the flick-switch the LCD starts showing the subject - bu it also starts the timer ( such as counting down from 25 secs ) this means I have to take my photo before the 25 seconds is up.

If I simple use the view finder all ok - but I would rather use the LCD screen for quick shots.

Using the LCD on a dSLR introduces camera motion that will increase the likely hood of causing blurred images.

Use the viewfinder for the best shots.

You have left the realm of P&S cameras and now have a real fully adjustable camera.

The reason the live view shuts off after 25 seconds is because your image sensor starts to get hot being turned on so long and the auto shutoff is there to protect it from damage.

Any dslr camera is designed, built and intended for serious photography. Point and shoot pocket toys are for snapping. If you can't, or don't want, to learn how to properly use a dslr camera then you probably should stick with the pocket toys.

"If I simple use the view finder all ok - but I would rather use the LCD screen for quick shots."

I use the viewfinder most of the time. For quick shots, I don't use the viewfinder at all. Just aim to whichever direction then shoot from the waist, from the hip, from the shoulder, from above everybody's heads. This is also to say that the LiveView button on my Pentax K-x has never been touched.