Croydon Council is holding a series of consultation meetings on masterplans for the areas around East Croydon and West Croydon stations and the latest stages of its new borough-wide planning policy. You can find the details here.
I would strongly you to attend one of these meetings. Most people only get involved with the planning system when someone applies to build something unsuitable near their home. But these individual applications are decided on the basis of the Council's planning policies - if an application is in line with Council policy, it will get approved even if local residents are opposed to it. So the time to get involved in when the policy is actually being drawn up ie right now!