I am interested Blackberry 10 development with HTML5/CSS, but I don't know what tools are needed for developing an application. Please explain the procedure to develop an application in Blackberry 10 using HTML5/CSS.
Thanks in advance.
Start with the official documentation. It gives an overview of WebWorks, and the tools needed.
https://developer.blackberry.com/html5/documentation/what_is_a_webworks_app_1845471_11.html
Use the Ripple emulator plugin for Chrome for testing:
https://developer.blackberry.com/html5/documentation/getting_started_with_ripple_1866966_11.html
Beginner tutorial:
https://developer.blackberry.com/html5/documentation/tutorial_javascript_geolocation.html
Signing keys overview:
https://developer.blackberry.com/html5/documentation/signing_your_app_1920008_11.html