Go to the symbol in the top left corner of your screen and click "About This Mac." to take this picture, hold down the key, the shift key and 4. the cursor turns into a little x and you drag it across the area on your screen you want to take a screen shot of. release and it will come up on your desktop as "Picture 1"
then, photobucket, and here!
I have a MacBook, super old, very little memory but I love her!