First, decide for which OS or mobile model you are going to development. If not sure then avoid working on latest version of OS (OS 6 is the latest). Reason being whatever is developed in OS 6 will only work with latest compatible phones. Few latest APIs may not work in older phones so make sure you start development using OS 4.7 or 5.0 version.
To start BlackBerry app development you need to do following:
1. Download and install BlackBerry eclipse plug-in and its free. Link: http://us.blackberry.com/developers/javaappdev/javaupdate.jsp (If you have done already, run sample and see if simulator is working properly)
2. To deploy app on real device you need to pay onetime fee of 20$. (This is not required for learning purposes)
The online application form for signing keys is available at link: https://www.blackberry.com/SignedKeys/
An administration fee of $20.00 USD will be charged to a valid credit card to complete the registration process. Typically, keys are sent via email within 48 hours of submitting the necessary forms, but occasionally the process can take up to 10 business days. For support contact BlackBerry support at 1-877-255-2377.
You can find more information and register for the code signing keys at
You can visit following links for more information related to BlackBerry App development:
1. Link: http://us.blackberry.com/developers/started/bbdevapproach.jsp
2. Link: http://us.blackberry.com/developers/started/mobiledev101.jsp