I agree with everything said here so far.
I have been dropping pounds myself after an over indulgent summer.
A couple of things that have worked for me in practice:
Eat earlier; I have to force myself to eat breakfast but it keeps me from cheating at 10:00am. Also keeping some Carrot sticks or Celery around helps if you want something to munch on. If you are going to eat a substantial meal once a day, try to make it lunch instead of dinner, dont go to bed with your belly the fullest it has been all day.
I keep my calories down to about 2000 per day.
Work out for at least 1/2 hour per day. Full body or large muscle group exercises are the best to keep your body burning calories throughout the day.
Along with the no fast food no white stuff as mentioned above, I try to not eat anything out of a package. Although Trader Joes does have some good alternatives (low cal, low fat, low carb).
Be careful of beverages. Some of these can appear to be "juice" or "Healthy" but are equal to half a cheesecake in a bottle. Water is always a good bet.
READ LABELS! Read the label of anything you put in your body. If it doesn't have a label it should be something you know to be ok for you.