TBH most people fail at losing weight and keeping the weight off because a lot of the diets they try are too radical. The best way to lose weight and keep it off is to make small changes while increasing the calories you burn.
Instead of surfing the net in your spare time or watching a crappy tv show on tv because there is nothing else to do go for a walk. When you only need a few things at the store ride your bike or walk there instead of driving.
Keep a diary of what you eat and the calories you consume. Try to keep your calorie intake under 2000 per day. You'll be surprised at how many calories you are actually eating. There are aps for most smart phones that let you keep track of calorie intake and calories burned. I use map my walk (keeps track of bike rides, jogs, etc. too) as well as 'lose it' on my iPhone. Lose It will tell you how many calories you can intake per day to achieve your weight loss goal. They also have a website if you do not have a smart phone.
Lose It website -
http://www.loseit.com/
Lose It iPhone app -
http://itunes.apple.com/us/app/lose-it/id297368629?mt=8
Lose It Android app - coming soon -
http://blog.loseit.com/2011/05/10/a-...android-users/
Map My Walk app -
http://www.mapmywalk.com/imapmy/iphone/