limit the number of nodes per User I'd like to limit the number of nodes that an authenticated user can create.
For example users can not create more than One post for specific Content Type. I am wondering how can I do so? Thanks..
The Node Limit module does exactly that:


  The Node Limit module allows administrators to restrict the number of nodes of a specific type that roles or users may create.


Among its features are:


  
  Per-role node limits
  Per-user node limits
  Per-time interval node limits
  Any combination of the above