Xcode let you "Build and Archive" your application to distribute to another people.
In Xcode, in the Build Menu, click Build and Archive to do so (make sure that you are in Device configuration).
When your application is build, Xcode will open the organizer windows, just go in "Archived Applications" tab to see your last build.
On the bottom you will see 3 buttons. In order to distribute the app to your boss, you should click on "Share Application".
XCode will propose you to sign application with a valid developer profile. You should create one for your boss (with his iPhone UDID like Tal Bereznitskey said).
Now you can choose to saved the ipa file on your disk or send it directly by email. Don't forget to join the provisioning file too.
Your boss as just to drag the provisioning profile into iTunes first, then the ipa file and synchronize to get the app on his phone.
Hope this helps !