For produce, at least, you can keep a list of the Dirty Dozen/Clean Fifteen. That way you can buy those things organic that are most likely to be contaminated and save your money on the "clean fifteen" that seem to be okay conventionally grown. Here's a link: http://www.pbs.org/wnet/need-to-know...roduce/616/://
Not to be a party-pooper (I was not always able to afford organic--in fact, I was not always able to afford food), but for those of us who are financially able, it isn't just about what is safe for us to eat, it is about the workers in the fields/orchards and about the run-off, too. That said, for those who can't afford it, this is a great way to parse out your limited income.
I would also suggest you try and buy organic dairy if you are eating dairy.
But, as a previous poster said, you have made the first step and that is a BIG one. Anything you can do to improve your diet over the Standard American Diet is going to help you in the long run.
Everything I eat has been proved by some doctor or other to be a deadly poison, and everything I don't eat has been proved to be indispensable for life. But I go marching on. ~George Bernard Shaw
Starting Weight (1/3/2011): 189
Current Weight: 173
Goal: To be in the best shape ever by age 50! (5/11/2012)