The website is for the NFTA
http://metro.nfta.com/
You can get around in the city and inner suburbs -- go to the 2nd ring and beyond, there are basically only commuter buses.
My husband and I drove in to the city for almost 30 years together and then one of us took a bus to our work from the first work..... it can be done. But.... The routes have to go where you want and they change at inconvenient times.. at any quarter of the year ( early Dec, early mar, early June, early Sept) routes change.