This guide will give you some great ideas to help you find the lowest fares on the internet.
Check all the big travel websites. That would be priceline.com, travelocity.com, cheapseats.com, and orbitz.com. Compare the prices that you see and decide if they are in your price range.
Book early. As the date of departure approaches, airlines tend to raise the prices the closer the flight gets. By booking early, you can avoid the price jack.
Avoid scheduling any travel over holidays or weekends. Holidays should be a no-brainer, but weekends may surprise you. Your best bet for travel prices will tend to be Tues-Thurs of the week. Check the above websites for these days to secure the lowest price.