Julie - check out a store called Fleet Feet - you've got one right there in Tulsa. Fleet Feet Tulsa
When I first started running, I had no clue what to buy. My local Fleet Feet put me on a treadmill and videotaped me walking and running to figure out the best shoes for my feet. It turned out that I was wearing shoes that corrected for a problem I didn't have and were totally wrong for me. They brought out five or six pairs - all different sizes but each fit perfectly (crazy sizing!) - and had me walk and run in them until I found the perfect shoes.
They were awesome and I buy all my gym shoes there now. I think they could answer all your questions and help you find the perfect pair of shoes.