Flaps
Sorry hun, maybe I didn't explain quite well enough.
You have a track pad and a clicker underneath it (that's how you move your pointer). Your desktop is the screen you have when all applications, folders etc are closed down (either standard Apple screen or another you may have selected). This may sound a bit basic, but let's go through it anyway.
Dragging:
With your right hand, move your pointer over the "Hard Disc" image on your desktop. When it's there, with your left hand, press and hold down the clicker. Now, with your right hand, move your finger across the trackpad as if you were moving the pointer. You'll notice the icon moves with the pointer (that's called 'dragging'). If you release the clicker, the image will 'drop' into the place you released it.
Dragging to desktop:
Essentially you are doing exactly the same thing, as above, but 'dragging' an image (or rather a copy of it) off the web page. Make sure your Safari window doesn't cover the whole screen ('Drag' the bottom right corner until the window fits the shape/size you want). Put the pointer over a picture on the web page and do exactly as you did above with icon, except dont release the clicker until the pointer is somewhere on the desktop. If it's an image that was 'placed', you should then see an icon of the file (image) on your desktop for the image that you have just dragged and dropped. You can then place in whatever folder you choose by opening your hard disc or user window and dragging it and releasing it when the chosen folder is highlighted. You can also import it into iPhoto by opening iPhoto and selecting File then Import (don't use the Import button under the piccies) and then selecting the file.
Sorry if I've covered too much stuff you already knew - but that's what "Drag to Desktop" means.
Trips