This is known as a high-key photo, which basically means it is brighter than usual.

The simplest way to go in that direction is to add positive exposure compensation to make the whole thing brighter without overexposing any important areas. Some cameras have a high-key mode that helps or you can tweak the brightness parameter (may be called differently depending on your camera brand).

This most likely won't get far enough. If you look at the darker parts of the images you linked (which are NOT really dark), there is a lot of noise. This suggests that the photographer increased the levels (Depending on the software: curves, shadows, fill) to bring what was originally very dark to a moderately bright level.

What you must do is make the darkest parts more-or-less midtone and the brightest parts as high as you can. This will result in a low-contrast image where most tones are bright. After that you may want to adjust color saturation as generally brightening an image results in a decrease in color saturation. It is easier to make those adjustments in a software which has curves or a histogram which you can manipulate. Lightroom and Photoshop have this.