To show a screencap of what you are doing you press the PrintScreen button on your keyboard. On a laptop it is usually beside F12 and on a computer keyboard it's normally above the number pad. It may be different on some though. After you've pressed the button press Ctrl+V(Paste) and your printscreen image should appear as a new image.
I'll show two images of when I work because I use two programs. I never blend in Photoshop, I do all my blending in Paint Shop Pro.
Nice idea MAGDA ...I don't use Photoshop...it's for me little bit complicated ....maybe in future I'll have time and energy for learning it....But I would like veeeeeeery much working with Photoshop...I use GIMP, but I'm learning still. I have couple of pics, if somebody wants look at them