Hi and welcome to the forum, hope you will find motivation and information here
As for your question, what worked for me was SLOWLY changing my habit, first i stop eating soda/energy drink/chips/chocolate everyday, and started to incorporate fruits and vegetables into my diet. Second was starting to do some exercise, i started to work back from my work everyday instead of taking the bus, it's about 45min walk i don't see the time go by listening to my ipod. Since when i joined this forum back in september i lost 50 pounds only by doing that, i recently joined the gym and been having sooooooo much fun, i'm feeling so good everytime i walk out the door at the gym, it's a really nice feeling.
Things that doesnt work, crash diet , starvation, trying to change everything at once. I been overweight for the majority of my life, and everything i had enough and wanted to change i would do everything at the same time, stop junk and eat boring stuff, start to run hardcore, and quit smoking. And it always only lasted about a week before i gave up.
Probably one of the biggest factor for me was to realise that loosing weight and getting fit is a long process, it's not something where you see result wittin a week. But after the first months on the right track i would see my progress and it would keep me motivated.
That's pretty much what i have on my mind right now, so good luck to you and remember it's a day by day thing, don't try to go too fast like most people do.
Cheers