While it's true that some people can lose weight without doing much exercise, research shows that some exercise can really accelerate the process, and help keep the weight off.
There are a million diet plans out there, and many will help you lose weight for a short period of time - but you really have to think about what you can sustain in the longer term to really be successful.
Please check out http://www.medhelp.org/user_journals/show/97218
which lists just a few solutions that you might find helpful. Take care.