Jay asks good questions!
In the meantime, some people like to dive in and make changes, others like to "baby step" and make a couple of changes here, a couple there. Speaking as a baby-stepper, I was overwhelmed when I started and just started by bringing lunch and snacks to work and watching portions. That's how I changed my eating the first month. After that, I started calorie counting...
Make a commitment, and then make a change!
My 5 C's of healthy living: Commitment to conscious control, with the understanding that choices have consequences