Most of all the articles about Mars terraforming focuses on warming the atmosphere. 2nd most popular topic as far as I know is the magnetic field that Mars lacks. Some other sources speak about toxic soil too. All of that sums up the terraforming as impossible today.
But what would happen if we already warmed up Mars (eg. with CO2)? It's atmosphere would consist of around 99% CO2 then and would lack oxygen and nitrogen. We could start production of oxygen using eg. ecopoiesis, but as it would lower the amount of CO2 wouldn't it also cool the atmosphere down again?
So let's put money and time aside: What would hypothetical chronological roadmap of what should be done in order to terraform Mars look like?