Jonathan did a terrific job lassoing and extracting his image to create this professional picture.
But you want to know a secret: I can lasso basic shapes - like windows - pretty darn good. When it comes to lassoing complex shapes - like people - more often than not, the lasso will go skitering cattywumpus across the screen with a mind of its own.
If what you want to do is extract the image of a person, you might find its easier to use Photoshop Elements' Magic Extractor.
Open your image (I'm working in Photshop Elements 5)
Click Image -> Magic Extractor
The Magic Extractor screen will open up

Click on the Foreground tool. Using the Foreground tool tells Elements what to extract.
Drag the tool - scribble style - on the part of the image (person) that you want to extract. The Photoshop Elements help files say you can just make a few dots here and there. I kind of like lines to pick up all the color variations. Don't try to draw the edges -- you might accidently pick up some background. Note that you can set the brush size in the right column of the screen.

Click on the Background tool. Using the background tool tells Elements what to exclude.
I usually set a fairly large brush size for the background tool. Slowly scribble around the entire background ... you do not need to make a solid mask. To finish up you may want to switch to a smaller brush and dab some dots.

Hit Preview
Use the "Add to Selection" and "Remove from Selection" tools to tidy up.

When your "extraction" looks about right, right OK.

Once an image is extracted, it can be moved and repositioned just about anywhere.
