Like the other posters stated, the best place to begin is with the person's background. The biggest mistake, as mentioned by bullgatortail, is being boring. Start with a quote by the person, the relevancy of the quote and then go into their background. It is always good to state why you chose the person to write on as well.
A bibliography would be a list of books the person has written. To find such a list, you can go to the person's web site or a place like Amazon.com. If you mean a biography, the person's web site is also a good source of information.
Most biographies begin by looking at the parents of the person the biography is focusing on and their background, as the above post suggests. This is helpful because obviously we are impacted greatly by the kind of people that our parents are, either for better or for worse, and often we can see where famous people found their inspiration or ambition to be famous in their field by looking at their parents and their various successes or failures.
All the answers given above are very helpful. Since parents have such a strong influence on the lives of their children, it might be especially helpful to spend some time discussing Foxx's parents and how they affected their son's life. It would also be good to consult interviews with Foxx himself. Although interviews, for a variety of reasons, are not always trustworthy, they usually provide many intriguing clues that can be jumping-off points for further research into a person's life. Good luck with your project! Remember that a tremendous amount of valuable information can be found these days by searching the internet.
If you can find an interesting and unknown fact about Mr. Foxx, you could begin with this as a "hook" to grab the reader's attention. Just be sure to use primary sources for your information and verify them.
Assuming you meant that you need to write a biography - a story of the life of Jamie Foxx - I would encourage you to identify key events in his life and feature one of them as your opening statement. This should help you to immediately capture the interest of your readers. You can then use the rest of your piece to explain how various other events or people shaped and influenced him, culminating with the event that you refer to at the start of your article.
For a biography, you want to research the important events and achievements of his life, as well as his personal history growing up, and his family, how he met his wife, birth of his children, etc.
For a bibliogrpahy you should find resources on his life and achievements that others could use. There will be a lot online, but not all of those are accurate or trustworthy, so you sift through them to find the ones you believe to be the most accurate and user friendly and put them into the format your teacher requires.
Most biographies begin with the person's birth and childhood. Start with his family. Where was he born? How was he raised? How does this past effect his current life?
Of course, you will probably want to focus somewhat on Jamie Foxx's rise to fame. You might want to take a closer look at his earlier career and what lead him to where he is now. Look for little know facts or information to make your paper more interesting.
For a biography, you should probably begin with a quick explanation of what Foxx is best known. Don't make the mistake of beginning with "Jamie Foxx was born on (date)... in (city)... to (parents)..." Boring! You may want to add that information in the second paragraph, but concentrate on the reasons for his popularity and fame, using any unusual info that you may find to create reader interest.
If you are in need of the proper format for a bibliography, check out the link below for more information.