Drink water! Lots of water!
Not sodas, not juices....water!
Water is one of the key elements to a healthy metabolism and if you're not getting enough plain-old-water, you're hindering whatever other efforts you're putting forth.
Here's a similar (and somewhat shortened) version of an article I read several years ago about the benefits of drinking water.
I'm sure someone a lot more educated in these matters (Moses, for instance) can expand on this, but however you decide to initiate your weight-loss program, please, don't forget to drink the water!
Randy