For starters, you can pick and try to choose those big booking agencies discussed in our Online Travel Booking and Bidding Agencies Forum.

As Aug 12 is quickly approaching and only a week away, I doubt you would be able to find the "cheapest" fare, compared to a booking made say 3 months ago. Most of the time, advanced planning is the key to a less expensive or affordable trip.

Make sure you keep all the travel documents current and ready, if you need any. Good luck!