Extract part of an Image?

I'm not very experienced with Photoshop yet, but starting with right tools is necessary. What is the best way extracting a part of a image from the background in a way that it has soft edges and every bit of it is still there when you finish?

Eero,
There's so many different ways to make selections in Photoshop. The trick is to know them all well enough to choose the best method for a particular job. There's all the marquee tools, the magic wand, the color range command; even the pen tool. I have tutorials for most of these. I'm working on a tutorial for the Extract command currently and that has some features which sound like they would suit your purpose. One of the best ways to select something with soft edges is by using a Quick Mask. In Quick Mask Mode, you literally "paint" a selection, so you can create a selection that has both hard and soft edges, based on the painting tool you use. If you use the Airbrush for example, you can choose soft edged brushes and paint at opacities lower that 100% to select precisely what you want in blurry or fuzzy areas. For a run-through on using this technique, see my tutorial, Creating a Mask: Face