How to redirect the user after login
You can use the Rules module.


  Example use cases
  
  Build flexible content publishing workflows changes Send customized
  mails to notify your users about important Create custom redirections,
  system messages, breadcrumbs, ... And many more...


To use that go to admin/config/workflow/rules/reaction/import and import this 
it will redirect user to admin/dashboard path after user logged in :

{ "rules_redirect_after_login" : {
    "LABEL" : "redirect after login",
    "PLUGIN" : "reaction rule",
    "OWNER" : "rules",
    "REQUIRES" : [ "rules" ],
    "ON" : { "user_login" : [] },
    "DO" : [ { "redirect" : { "url" : "admin\/dashboard" } } ]
  }
}


You may also build a custom module and use  hook_user_login and do something on the lines of :

function hook_user_login(&amp;$edit, $account) {
     $_GET['destination'] = 'node/25';
 }