It means you are very lucky and will get pell money. My EFC for 08/09 is $7,000 and I have been unemployed for over a year.
You cannot make up your EFC with loans. Your EFC drops the total amount of aid that is available to you. If your cost of attendance is $10,000 (usually includes tution, books, room and board, plus various expenses) and your EFC is $5,000 that means that you can only get $5,000 worth of financial aid TOTAL, including loans, scholarships, and grants.
Thanks to my ridiculously high EFC I can only take out a total of about $5,000 aid for 08/09. That's $2500 a semester and my tuition alone is around $1200. It doesn't leave much for other expenses and I have to drive 70 miles a day to get to school.
An EFC of 766 would be a dream. Don't worry about it. A $766 reduction in the amount of aid available to you won't be a problem. They usually estimate books based on campus bookstore prices, but you can get your books from ebay or amazon
market place for a fraction of the price. That will easily offset a $766 EFC.