go you!
suggestions:
a whole lot of folks i know are doing the south beach diet -- it's carb-restricted, like atkins, but it doesn't have that "what, so you'll never eat a cookie again?" level of restriction. i don't know much more about it because i kind of tune people out when they start south-bitching (as we call it). another bunch of folks i know continues to swear by weight watchers (both at regular meetings and online), but really, it doesn't matter what the diet is as long as it's healthy and you can live with it and won't get all frustrated and go binging.
you might try reading
the book "intuitive eating". it's more about dieting in general and the stuff that goes on in your head (and why people "screw up" diets) than just the "here's what to eat".
if you're looking at running, the marathoners i work with strongly suggest
http://www.coolrunning.com/
i've been doing the "work out a few times a week and eat less crap" diet plan and it's been doing pretty well for me.
but it sounds like you've got an achievable goal and a good plan. good luck!