The process for developing and deploying applications to the PlayBook simulator is a little different then that of the device. For the simulator you simply place it into development mode and you can deploy your un-signed applications. There are 2 additional steps that you need to do in order to deploy and debug your applications on the device.
The first step is to create and upload a debug token to the device. This entire step can be done with the command line, but is much easier to do with the Flash Builder plugin. Before you can create your debug token you must sign up for signing keys. This can be done from the BlackBerry Developer Zone form found here. You should get your keys the following day so may sure to sign up for your keys early so you aren’t waiting a day to develop for the device. What the debug token does is associates your application with you and your device. Watch the video below for a complete list of steps on how to create and upload.
The second thing you need to do is add the author and authorId tags to your blackberry-tablet.xml file. This associates your application with your debug token and allows it to run on any device with that debug token installed on it. With this you should be able to deploy your application to your device as many times as you need.
The alternative to using debug tokens is to sign your application every time you want to load it on to the device. This would mean that for every little code change it would need to be re-signed. There are 2 things to keep in mind when signing your application. The first is that the version number has to be incremented every single time you sign your application. If you try to sign an application with the same version number it will throw an error. You can read this page for more information about assigning a version number to your application. The second thing to keep in mind is you need to be connected to the internet in order to sign your application. Having to do these 2 things every time you wanted to test your application on the device is unreasonable, which is why debug tokens were created in order to provide greater flexibility in developing and deploying to the actual device.
If you have gone through and followed all the steps in the video below for creating debug tokens, your applications is all ready to be signed. It is as simple as right clicking on the project and selecting Export. I hope the video below helps you get your application on deployed to the device.