recently facebook introduced timeline, I noticed that many of my friends are added cover photos properly. when i add cover photo to time line it is not fit to the page.
To add a cover image to your timeline:
Go to your timeline
Click Add a Cover
Choose whether you want to upload a new photo or pick a photo from one of your existing photo albums
Once you choose a photo, you can reposition it by clicking on the image and dragging it up or down