Four things are required: an certificate for each development / build machine, an identifier for your app, registered test devices and an provisioning profile which holds these things together. The first two things I already explained in my previous article Part 1: Certificates, Identifiers, Test Devices and Provisioning Profiles
To deploy an app directly to an device, you have to register the device as an test device. You need to declare a name and the UDID of your device.
You can get the UDID of your device via Itunes. Normally your serial number is shown in Itunes, but when you click on it, the UDID appears. There are also several other possibilities to get the UDID, for example via registry, but it is much more complicated.
Provisioning profiles holds all the information together, certificate, app identifier and test devices. Because a certificate is referenced, you need a seperate provisional profile for development and distribution certificate. The provisioning profiles have to be downloaded and installed on every mac you want to build the app. So normally every developer with a seperate developer certificate and device creates a provisioning profile for their own.
The provisioning profiles can be easily downloaded via Xcode if you have the required certificate installed.