The Green Card Lottery closes November 2, 2013 at noon EDT (GMT-4).
You should go to http://www.dvlottery.state.gov/ to submit your official entry at no charge. Instructions on how to submit digital photos are on that same page. That web site is very busy...just keep trying to get in.
After submitting your official entry at the web page stated above, you will automatically receive an instant message confirming receipt of your entry. Be sure to keep a copy of that message, as you will need the information they give you to later track your entry.