[chef] How to trigger up auto configuration upgrade by chef!

hi, Everyone

  I am trying chef for its configurtion management features. After building 
up a system consisted of laptop, server, and client, I wonder if chef a good 
helper to upgrade a certain configuration item on a batch of nodes 
automatically. If possible, please provide a guidline how to do this. Should 
I change the cookbook on server then ssh to each client to run "chef-client" 
and trigger up the upgrade task? If any reference has come up related with my 
goal, please help attach them to me. Thanks a lot.

Cindia